WO1997010659A1 - Procede et dispositif de compression et de chiffrement de donnees - Google Patents
Procede et dispositif de compression et de chiffrement de donnees Download PDFInfo
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- WO1997010659A1 WO1997010659A1 PCT/JP1995/001815 JP9501815W WO9710659A1 WO 1997010659 A1 WO1997010659 A1 WO 1997010659A1 JP 9501815 W JP9501815 W JP 9501815W WO 9710659 A1 WO9710659 A1 WO 9710659A1
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- data
- compression
- symbol
- encryption
- bit string
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- 238000000034 method Methods 0.000 title claims description 143
- 238000003860 storage Methods 0.000 claims abstract description 61
- 230000010365 information processing Effects 0.000 claims abstract description 35
- 238000012545 processing Methods 0.000 claims description 106
- 238000007906 compression Methods 0.000 claims description 101
- 230000006835 compression Effects 0.000 claims description 100
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- 238000013144 data compression Methods 0.000 claims description 27
- 230000006837 decompression Effects 0.000 claims description 25
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Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
- G11B20/0021—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/00007—Time or data compression or expansion
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
- H03M7/30—Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
- H03M7/40—Conversion to or from variable length codes, e.g. Shannon-Fano code, Huffman code, Morse code
Definitions
- the present invention relates to data compression and encryption, and more particularly to a data compression / encryption method and apparatus for improving processing efficiency and reducing power consumption when performing both compression and encryption on data.
- compression encryption data that is indispensable because the bandwidth is small and interception is easy.
- portable computers which are rapidly spreading in recent years, battery life is an important issue, and processing methods suitable for saving power are becoming important. From the above, an efficient and low power consumption compression / encryption technology is essential.
- data is first compressed and written to a secondary storage device such as a hard disk, and then the compressed data is read from the secondary storage device and encrypted.
- a secondary storage device such as a hard disk
- the compressed data is read from the secondary storage device and encrypted.
- the same encryption was performed as for the uncompressed data without considering that the data was compressed.
- the data is first decrypted and written to the secondary storage device, and then decrypted. The data was read from the secondary storage device and restored.
- An object of the present invention is to integrate the processing of compression and encryption, and eliminate the need for interlocking the compression, encryption, and decryption and decompression via a secondary storage device.
- An object of the present invention is to provide a data compression / encryption method and apparatus capable of improving efficiency and reducing power consumption. Disclosure of the invention
- the amount of memory required for the compression encryption processing and decryption decompression processing is the main capacity of the information processing system.
- the amount of data to be processed at a time may be limited so as not to exceed the capacity of the storage device.
- the amount of data to be processed at one time is divided so that the amount of memory required for the compression encryption process and the decryption / decompression process does not exceed the capacity of the main storage device of the information processing system. Then, data compression and encryption are repeated and executed sequentially, and the entire set of data is compressed and encrypted.
- the first method of the present invention is a method for providing an information processing system having a data compression means and a decompression means, wherein an encryption means and a decryption means are provided, and the compression means and the encryption means are applied to data.
- the compression and encryption L is decrypted so that the required amount of memory does not exceed the capacity of the main storage of the information processing means when applying the decryption means and decompression means to the data.
- the compounding t is compounded and restored.
- a method based on an adaptive stochastic model For example, adaptive Huffman coding.
- the compression encryption method of the present invention can be applied to the above (1) and (2). Also, the present invention cannot be directly applied to (3), but can be applied to the combination of (1) and (3) or (2) and (3).
- the appearance probability of each symbol is obtained by checking the frequency of each symbol in the data. Based on the appearance probability of this symbol, the correspondence information between the symbol and the bit string (Huffman tree in the case of Huffman coding) is generated. At this time, a symbol with a higher appearance probability is associated with a shorter bit string.
- the data is then compressed by converting the symbols in the data into the corresponding bit strings.
- the decompression process receives the compressed data and the symbol-to-bit-string correspondence information (or the frequency and probability of appearance of the symbol for generating it), and restores the original data by inverting the bit sequence to symbols.
- the encryption purpose can be achieved by encrypting only the symbol-bit string correspondence information without encrypting the compressed data itself.
- the amount of information corresponding to one bit string of symbols is extremely small compared to compressed data, so the amount of encryption processing and the amount of corresponding decryption processing is smaller than the conventional method of encrypting compressed data itself. Can be greatly reduced. That is, the second method of the present invention encodes symbol-bit string correspondence information in compression based on a fixed probability model.
- the correspondence between symbols and bit strings should be completely different if the data is slightly different.
- the length of the corresponding bit string is determined depending on the appearance probability of the symbol, but the array of 0s and 1s at that length has a degree of freedom. There is. For example, even if the length of the bit string corresponding to the symbol a is determined to be 4, the corresponding bit string has degrees of freedom such as 0000, 0101, and 111. Therefore, the bit string corresponding to the 'symbol is selected from the above-mentioned plurality of possibilities depending on an accidental or stochastic factor such as a random number.
- the association between the symbol and the bit string is performed by accident or by using a calculation based on a probability.
- the correspondence between the data and the bit string may be changed during the data processing.
- the association between the symbol and the bit string is changed during the data processing.
- a second encryption means may be provided, and the encrypted data obtained by the above method may be further encrypted.
- the second encryption means requires more simple processing than the conventional encryption means for simple compressed data.
- the expected value of the appearance probability is used instead of examining the data in advance and finding the appearance probability of the symbol as in the fixed model.
- As an initial expected value of the probability of occurrence for example, the probability of occurrence of all symbols is expected to be equal.
- the symbol is converted to a bit string and the estimated value is corrected (increase the estimated probability of occurrence of the processed symbol and decrease the estimated probability of occurrence of other symbols).
- the entire data is compressed by repeating the conversion of the above symbols into bit strings and correction of the expected value of occurrence probability.
- the restoration process receives the compressed data and restores the data by repeating the inverse conversion from the bit string to the symbol and the correction of the appearance probability estimation value, using the initial expected value of the same occurrence probability as the compression process.
- the sixth method of the present invention compresses the head of the compressed data in the compression based on the adaptive probability model.
- the following decoding method can be considered for the above method.
- the correspondence between symbols and bit strings can be performed by accident or by calculation based on probability. it can.
- the correspondence between the bit strings of the symbols may be changed based on information other than the expected value of the appearance probability of the symbols.
- the length of the corresponding bit string is determined depending on the expected value of the occurrence probability of the symbol, but the arrangement of 0s and 1s at that length has some degrees of freedom. Therefore, during the data processing, the association between the symbol and the bit string may be changed regardless of the appearance probability of the symbol.
- the seventh method of the present invention changes the correspondence between symbols and bit strings based on information other than the appearance probabilities of symbols during data processing.
- the amount of memory required when applying compression means and encryption means to data and the amount of memory when applying decryption means and decompression means to data are represented by the information.
- the amount of data used for compression and encryption or decryption and decompression is set so as not to exceed the capacity of the main storage device of the processing system. This eliminates the need to read and write intermediate results to and from secondary storage. Thus, efficiency can be improved and power consumption can be reduced.
- the symbol-bit string correspondence information is encrypted, so that the compressed data cannot be restored, and the same effect as the encryption of the compressed data itself can be obtained. it can. While the amount of compressed data is usually several kilobytes to several megabytes, the amount of symbol-bit string correspondence information is about one byte of the number of types of symbols, which is negligibly small. Thus, according to the present method, the efficiency of encryption and corresponding decryption can be improved.
- the correspondence between the symbol and the bit string is determined by accident or using a calculation based on probability, so that every time the method is started, the correspondence between the symbol and the bit string is completely different. Therefore, it is difficult to estimate the tendency of the correspondence between symbols and bit strings, and the strength of encryption increases.
- the association between the symbol and the bit string is changed during the data processing, so that the repetition pattern in the data does not appear in the symbol data.
- the strength of the ⁇ symbol increases.
- the encrypted data by the above method is further encrypted by the second encryption means, so that the encryption strength is increased. Because it is double encryption, the second A simple encryption means is sufficient, and can improve the efficiency of encryption. In general, if the encryption is simple, the corresponding decryption is also simple, so that the efficiency of the decryption can be improved.
- the head of the compressed data is encrypted, which makes it difficult to predict the appearance probability of the symbol in the subsequent part, and as a result, the entire compressed data is encrypted.
- the efficiency can be improved and the corresponding decryption efficiency can be improved compared to the conventional method of encrypting the entire compressed data.
- the association between a symbol and a bit string is suddenly changed during data processing based on information other than the expected value of the symbol appearance probability, so that the repetition pattern in the data is encrypted. Does not appear in the data. Thus, the strength of the encryption increases.
- FIG. 1 is a flowchart showing a compression processing method in the first embodiment of the present invention
- FIG. 2 is a diagram showing a functional configuration of the first embodiment of the present invention
- FIG. 3 is Huffman coding.
- FIG. 4 shows an example of correspondence information (Huffman tree) between symbols and bit strings in FIG. 4.
- FIG. 4 is a flowchart showing a method of associating symbols and bit strings based on random numbers in the first embodiment of the present invention.
- FIG. 5 is a flowchart showing a method of generating a plurality of correspondence information between symbols and bit strings in the first embodiment of the present invention.
- FIG. 6 is a modification of the correspondence information between symbols and bit strings in FIG.
- FIG. 7 shows an example, FIG.
- FIG. 7 is a flowchart showing a restoration processing method in the first embodiment of the present invention
- FIG. 8 is an intermediate result of generation of correspondence information (Huffman tree) between symbols and bit strings.
- Fig. 9 shows the correspondence between symbols and bit strings
- Huffman Fig. 10 shows an example of the intermediate and final results of the generation of the tree
- Fig. 10 shows an example in which the correspondence information between the symbols and bit strings in Fig. 9 is modified
- Fig. 11 shows the compressed and encrypted data.
- FIG. 12 is a flowchart showing an example of data
- FIG. 12 is a flowchart showing a method of generating a plurality of types of correspondence information between symbols and bit strings in the second embodiment of the present invention
- FIG. 13 is a second embodiment of the present invention.
- FIG. 14 is a diagram showing an example of a data format for storing a plurality of correspondence information between a symbol and a bit string in the embodiment.
- FIG. 14 is an expression for switching the correspondence information between a symbol and a bit string in the second embodiment of the present invention.
- Raw FIG. 15 is a diagram showing a functional configuration of the third embodiment of the present invention
- FIG. 16 is a flowchart showing a compression processing method of the third embodiment of the present invention.
- FIG. 17 is a flowchart showing a method of associating symbols and bit strings based on function values in the third embodiment of the present invention
- FIG. 18 is a reconstruction of the third embodiment of the present invention.
- 5 is a flowchart showing a processing method.
- FIG. 1 shows a functional configuration diagram of the first embodiment.
- Block 201 and block 215 are complete information processing systems, respectively. Data can be sent from block 201 to block 215 via a communication line.
- Block 202 is processing realized by the central processing unit and the input / output device, and the input / output 203, the control 204, the probability information generation 205, the compression 206, the encryption 207, It consists of each process of transmission 208.
- Block 209 is a main memory implemented by a RAM (random access memory) or the like, and stores appearance probability information 210.
- Block 211 is a secondary storage realized by a hard disk or the like, and stores raw data 212, compressed and encrypted data 211 and encryption correspondence information 214.
- Block 2 16 is processing realized by the central processing unit and input / output device, and each processing of input / output 2 17, control 2 18, reception 2 19, decoding 2 2 0, and restoration 2 2 1 Consists of
- the block 222 is a main memory realized by a RAM (random access memory) or the like, and stores correspondence information 222.
- Block 224 is secondary storage realized by a hard disk, etc. The encrypted data 2 26 and the raw data 2 27 are stored.
- Input / output 203 inputs raw data and stores it in secondary storage 211.
- a compression encryption command and a data transmission command are input and passed to the control 204.
- the control 204 receives the compression / encryption command, it starts the probability information generation 205, the compression 206, and the encryption 207 sequentially and performs a step of compressing and encrypting a part of the raw data.
- the whole raw data is compressed and encrypted and stored in the secondary storage 2 1 1.
- the correspondence information between the symbol and the bit string obtained in the process (referred to as symbol-one-bit string correspondence information) is encrypted and stored in the secondary storage 211.
- the amount of raw data to be compressed and encrypted in one step is set so that the amount of memory required for processing does not exceed the main storage capacity of the information processing system 201. Further, when the control 204 receives the transmission command of the compressed encrypted data, the control 204 starts the transmission 208 to transmit the compressed encrypted data and the encrypted symbol-one bit string correspondence information to the information processing system 210. Send to 5.
- Probability information generation 205 calculates the appearance probability of the symbol in the raw data by counting the frequency of appearance of the symbol in the raw data, and passes it to the compression unit 206.
- the compression unit 206 generates correspondence information between the symbol and the bit string based on the appearance probability information of the symbol, and stores the information in the main memory 209. Also, referring to the symbol and the bit string correspondence information, a part of the raw data 212 is compressed and encrypted and passed to the encryption 207. This process will be described later in detail with reference to FIGS. 1, 3, 4, 5, and 6.
- the encryption 207 receives the compressed data from the compression 206, encrypts it, and stores it in the secondary storage 211.
- the corresponding information of the symbol and the bit string is read out from the main memory 210, encrypted, and stored in the secondary memory 211.
- the transmission unit 208 transmits the compressed encrypted data and the encrypted symbol-bit string correspondence information to the information processing system 215.
- the input / output 2 17 inputs the decryption restoration command and passes it to the control 2 18. Also, it outputs the raw data 2 27 in the secondary memory 2 2 4.
- Control 2 18 is decryption 2 2 0
- the decryption and restoration of the compressed encrypted data is repeated by sequentially starting the decryption and restoration 2 2 1 and repeating the steps of decrypting and restoring the compressed encrypted data 2 2.
- Stored in memory 2 2 4 At this time, the amount of compressed encrypted data to be decrypted and restored in one step is set so that the amount of memory required for processing does not exceed the main storage capacity of the system 215.
- the reception 219 receives the transmission 209, the encrypted symbol-bit string correspondence information and the compressed encryption data, and stores them in the secondary storage 224.
- the decryption 220 decrypts the encrypted symbol one-bit string corresponding information by the inverse conversion of the encryption 207 and stores it in the main memory 222.
- the compressed encrypted data is decrypted and passed to decompression 2 2 1.
- the decompression 222 decompresses the compressed data based on the symbol-bit string correspondence information in the main memory 222 and stores it in the secondary memory 222. . This processing will be described later in detail with reference to FIG.
- FIG. 1 is a flowchart showing the operation of the compression unit 206 of FIG.
- step 101 a random number is generated, and based on the value of the random number, one-bit symbol string correspondence information is generated from the appearance probability information of the symbol, and stored in the main memory 209.
- This symbol one bit string correspondence information is called initial symbol-bit string correspondence information.
- the symbol-bit string correspondence information is represented by a binary tree (called a Huffman tree) as shown in Fig. 3.
- a Huffman tree each symbol is placed at a leaf node (terminal node), and a sequence of 0s and 1s added to the branch from the root node to the symbol represents a bit sequence corresponding to the symbol.
- a corresponds to 0 0
- b corresponds to 0 1 1
- e corresponds to 1. Details of step 101 will be described later with reference to FIG.
- step 102 other symbol-bit string correspondence information is generated from the initial symbol-one bit string correspondence information.
- step 103 one of the above initial symbol-bit string correspondence information and other symbol one-bit string correspondence information is selected and used as use correspondence information.
- step 104 the first symbol of the target raw data (the part designated by control 204 in the entire raw data) is set as the current symbol.
- Step 105 converts the current symbol into a bit string based on the usage correspondence information.
- Step 106 determines whether all the target raw data has been processed. If all processing has been completed, the process returns. Otherwise, go to step 107 and make the symbol next to the current symbol a new current symbol.
- step 108 the use correspondence information is changed to the symbol one bit string correspondence information other than the current use correspondence information, and the process returns to step 105. This change is made, for example, by the following method.
- step 101 in FIG. 1 a Huffman tree in which 0s and 1s are not added to the branches is generated by a conventional Huffman tree generation method as shown in the Data Compression Handbook, Toppan, pages 21 to 60.
- 0 or 1 is added to the branch of the Huffman tree by applying the processing shown in FIG. 4 to the root node of the Huffman tree.
- Step 1 0 1 1 determines whether the node is a leaf node. Returns if it is a leaf node (not initially). If not, proceed to Step 1 0 1 2 to generate a random number. In step 101, it is determined whether the generated random number is even or odd. In the case of an even number, the process proceeds to step 101, and in the case of an odd number, the process proceeds to step 101.
- Step 1 0 14 adds 0 to the left branch and 1 to the right branch of the node.
- Step 1005 adds a value opposite to that of step 101-4.
- this processing is applied recursively to the left child node of the node.
- this processing is recursively applied to the right child node of the node.
- step 201 the number of stages of the initial symbol one bit string correspondence information obtained by the method shown in FIG. 4 is obtained, and is substituted into a variable n.
- n 3.
- Step 1 0 2 2 assigns a binary number starting from n digits 0 to variable a.
- Step 1023 increases the value of a by one.
- step 1024 the value of a is determined to be 1 digit, and the values are set to ml, m2,... Mk. For example, if a is 0 1 1, the digits with a value of 1 are 1 and 2 (from the right end).
- Step 1025 is to obtain the initial symbol one-bit string correspondence information, m1, m2,... Mk, by exchanging 0 and 1 for the mk-stage branch, and obtain another symbol one-bit string correspondence information.
- the initial symbol-bit string correspondence information is the Huffman tree in FIG. 3 and a is 0 1 1, the Huffman tree in which 0 and 1 are exchanged for the first and second branches in FIG. 3 (FIG. 6) Is another symbol-bit string correspondence information.
- 2 n powers of 1 symbol-bit string correspondence information is generated, and 2 n power correspondences are obtained together with the initial symbol-bit string correspondence information.
- Step 701 generates other symbol one bit string correspondence information from the initial symbol-bit string correspondence information.
- the same processing as step 102 in FIG. 1 is used. Therefore, if the initial symbol-bit string correspondence information is equal to the initial symbol-bit string correspondence information of the compression 206, all the symbol-bit string correspondence information becomes equal to the compressed symbol-one bit string correspondence information.
- step 720 one symbol / one bit string correspondence information is selected and used as use correspondence information.
- This process also uses the same process as step 103 of the compression. Therefore, the same use correspondence information as in the compression is selected.
- step 703 a bit string corresponding to the symbol is cut out from the head of the compressed data based on the use correspondence information.
- step 704 the original raw data is obtained by converting the bit string into a symbol.
- Step 705 determines whether or not all the compressed data has been processed. If all processing is completed, return. If not, go to Step 706 Removes the processed bit sequence from the compressed data.
- step ⁇ 07 the use correspondence information is changed to other symbol one bit string correspondence information, and the process returns to step 703. This process uses the same process as step 108 in FIG. Therefore, the same usage correspondence information as in the compression is selected.
- the control 204 activates the probability information generation 205, obtains the appearance probability of the symbol in the raw data, and passes it to the compression 206.
- the total number of symbols is 12 including the space between s and t.
- the appearance probability of t is 3Z12
- the appearance probability of h is 2-12.
- the compression 206 compresses the raw data in the secondary storage 211 based on the symbol appearance probability information by the processing of FIG.
- step 101 first, a Huffman tree to which 0 and 1 are not added is generated based on the appearance probability of a symbol by a conventional method.
- a Huffman tree to which 0 and 1 are not added is generated based on the appearance probability of a symbol by a conventional method.
- 0 and 1 are added to the branches of the Huffman tree by applying the processing in FIG. 4 to the root node of the Huffman tree.
- Step 1 0 1 1 determines whether the node is a leaf node. Here, it is No because it is the root node.
- Step 101 determines whether r is even. Here, it is No.
- Step 1 0 15 adds 1 to the left branch and 0 to the right branch of the node.
- Step 106 is to recursively apply this process to the left child node of the node.
- step 101 is No.
- Step 1 0 1 3 becomes Yes.
- Step 1 0 14 adds 0 to the left branch and 1 to the right branch of the node.
- the Huffman tree at this point is shown in Fig. 9, block 901.
- step 106 this processing is reapplied to the left child node of the node. It is assumed that the Huffman tree of the block 902 is finally obtained by repeating the same processing. This is the initial symbol one bit string correspondence information.
- step 102 other symbol-bit string correspondence information is generated from the initial symbol-bit string correspondence information of the block 902 by the processing of FIG. Step 1 0 2
- Step 1 finds the number of steps in the Huffman tree of block 902 and substitutes it for the variable n.
- n 4.
- Step 1 0 2 2 assigns a binary number 0 0 0 0 consisting of 4 digits 0 to the variable a.
- Step 1 0 2 3 substitutes 0 0 1 into a. Steps
- Step 1 0 25 stores the result of exchanging 0 and 1 of the first-stage technique of block 902 as another symbol-bit string correspondence information.
- step 1005 the second branch of block 902 is changed to obtain block 1002.
- the first and second branches of block 902 are changed to obtain block 003.
- 15 (2 4 -1) symbol-bit string correspondence information is obtained, and 16 types of symbol-bit string correspondence information including initial symbol 1-bit string correspondence information are obtained. obtain.
- the block 103 selects one of the 16 types of symbol-bit string correspondence information described above and uses it as usage correspondence information.
- initial symbol-bit string correspondence information that is, block 902 is selected.
- Block 104 sets the first symbol of the raw data as the current symbol.
- t is the current symbol.
- Block 105 is the usage support information Based on the information, convert t to the corresponding bit sequence. Here, it is converted to 01.
- Block 106 determines whether all the raw data has been processed. Here, it is No.
- Block 107 sets the symbol following the current symbol as the current symbol.
- h is the current symbol.
- Block 108 changes the use correspondence information to other symbol-bit string correspondence information by the method described above.
- the current use correspondence information is the initial symbol-bit string correspondence information, that is, the 0th symbol-bit string correspondence information. If the bit sequence 0 1 corresponding to the above U is regarded as a binary number, its value is 1. Therefore, 1 is added to the number of the current symbol-bit string correspondence information, and the first symbol-bit string correspondence information is used as new use correspondence information. This is the Huffman tree for block 1001.
- Block 106 becomes No.
- Block 107 has i as the current symbol.
- the current use correspondence information is the first symbol-bit string correspondence information and the bit string 0 1 0 corresponding to h is 2, the third symbol one bit string correspondence information Is used as correspondence information.
- the raw data is converted into compressed data by the same processing.
- FIG. 11 shows the compressed data. However, bit strings below the third symbol are omitted.
- the encryption 207 further encrypts the compressed data by a conventional encryption method, and stores it in the secondary storage 211. Also, the initial symbol-bit string correspondence information is decoded and stored in the secondary storage 211.
- the input / output 203 inputs the transmission command and passes it to the control 204.
- the control 204 activates the transmission 208 to transmit the compressed encrypted data and the encrypted initial symbol one bit string correspondence information to the information processing system 215.
- the reception 2 19 receives the above-mentioned compressed encrypted data and the encrypted initial symbol-bit string correspondence information, and stores them in the secondary storage 2 2 4.
- the input / output 2 17 inputs a decryption decompression command and passes it to the control 2 18.
- the control 218 activates the decryption 220 and the recovery 221 to decrypt and recover the compressed encrypted data.
- compression ciphers Instead of processing the data all at once, the data is divided and processed so as not to exceed the memory capacity of the information processing system-215. Here, since the data volume is small, the processing is performed at one time.
- the decryption 220 decrypts the encrypted initial symbol-bit string correspondence information by a conventional decryption method, and stores the result, ie, the block 902, in the main memory 222. Further, the compressed encrypted data is returned to the data before being subjected to the encryption 207, that is, the compressed data shown in FIG.
- the decompression 221 decompresses the compressed data of FIG. 11 based on the initial symbol-bit string correspondence information in the main memory by the processing of FIG.
- step 701 other symbol-bit string correspondence information is generated from the initial symbol-bit string correspondence information of block 902 by the same processing as in step 102.
- step 702 one symbol-bit string correspondence information is selected by the same processing as step 103 and used as use correspondence information.
- the initial symbol-bit string correspondence information (block 902) is selected.
- step 703 01 is cut out from the head of the compressed data in FIG. 11 based on the use correspondence information.
- Step 7 0 4 converts 0 1 to t.
- Step 705 becomes No.
- step 706 0 1 is removed from the head of the compressed data in FIG.
- step 707 the second symbol-bit string correspondence information is set as new use correspondence information by the same processing as step 108.
- the compressed data is converted into raw data and stored in the secondary storage 224 by the same processing.
- the input / output 2 17 receives the output command and outputs the raw data in the secondary memory 2 24.
- the raw data can be compressed and encrypted, and the compressed and encrypted data can be decrypted and restored to restore the original raw data.
- Compression and encryption at one time so that the amount of memory required when compressing and encrypting data and the amount of memory required when decrypting and restoring data do not exceed the main storage capacity of the information processing system.
- the encryption processing is applied to the compressed data and the information corresponding to the symbol-bit string.
- (1) generation of symbol-one bit string correspondence information based on random numbers, (2) modification of symbol-one bit string correspondence information, and (3) encryption to symbol one-bit string correspondence information (4) Encrypt raw data by applying encryption to compressed data.
- the processing of (1) is the addition of 0 and 1 to the branches of the Huffman tree.
- the Huffman tree is a tree having leaf nodes only for the type of symbol, and the number of branches is (type of symbol-1) X 2. Since the types of symbols are at most about 300, the processing of (1) is a processing of adding 0 or 1 to branches of at most about 600, which is complicated to compress compressed data of several kilobytes to several megabytes. It can be executed in a negligible amount of time compared to the conventional process that adds encryption. Similarly, the processing time of (2) is also negligibly small. Regarding (3), since the amount of symbol-bit string correspondence information is extremely small compared to compressed data, the encryption time is negligibly small. For the encryption processing in (4), simple processing is sufficient for the following reasons.
- the time of the encryption processing of (4) can be made shorter than that of the conventional encryption processing. As described above, according to the present embodiment, it is possible to reduce the time for compression and encryption.
- the decryption processing is applied to the compressed encrypted data and the information corresponding to the encrypted symbols and bit strings.
- (1) application of decryption processing to symbol one bit string correspondence information, (2) modification of symbol one bit string correspondence information, and (3) decryption processing to compressed encrypted data Decrypts the compressed encrypted data by applying.
- the processing times of (1) and (2) are so small that they can be ignored, as in the case of encryption.
- the decryption process is also simple. Therefore, the time for the decoding process (3) is also shorter than that of the conventional decoding process. As described above, according to the present embodiment, the time for decoding and restoring can be reduced.
- the second embodiment is a modification of the first embodiment.
- a symbol is converted into a bit string by using the plurality of symbol-bit string correspondence information by the following processing in order to conceal a repeated pattern in the raw data.
- the concealment of the repetitive pattern is made more complete by the following method.
- step 102 more symbol-bit string correspondence information is generated.
- step 108 prepare a plurality of equations for calculating the number of the symbol-bit string correspondence information to be used next, and in step 108, use one of them to The number of the symbol-bit string corresponding information to be used is determined. Which formula to use is determined based on the common parameters that are kept secret except for the sender and receiver of the data, set to compression 206 and decompression 222. .
- the above (a) can be realized by using the method shown in FIG. 12 instead of the method shown in FIG.
- step 1021 the root of the initial symbol-bit string correspondence information and the number of intermediate nodes are assigned to a variable m.
- step 1022 numbers 1 to m are assigned to the roots and intermediate nodes of the initial symbol one bit string correspondence information.
- Step 1 0 2 0 3 assigns a binary number consisting of m digits of 0 to the variable a.
- Step 10 204 increases a by one.
- step 1205 a digit having a value of 1 is obtained from a, and m 1, m 2,... Mk is set.
- Step 1206 is to exchange the values (0 or 1) of the left and right branches from the mk-th node of the initial symbol-bit information in the initial symbol-bit information into another symbol one-bit sequence.
- the initial symbol 1-bit string correspondence information is a binary tree, with two branches from each root and intermediate node.
- 2 m-th symbol-bit string correspondence information including the initial symbol one bit string correspondence information can be obtained.
- This is more than the 2 n -th symbol-bit string correspondence information in the first embodiment.
- the symbol-bit string correspondence information of the present embodiment is one hundred twenty-eight, and the symbol-bit string of the first embodiment is There are 16 types of correspondence information.
- the symbol-bit string correspondence information for the same raw data has the same binary tree structure and differs only in the value of 0 or 1 added to the technique. Therefore, we represent multiple symbol 1-bit string correspondence information by adding multiple values to a single binary tree technique. For example, the three binary trees in FIG. 10 are collectively represented as shown in FIG. Next, the method of obtaining a plurality of expressions in the above (b) will be described with reference to FIG. Here, a plurality of expressions for calculating the value from V and w and having 10 characters are obtained.
- Step 1401 assigns the variable SYM—SET a set of nine characters V, w, +, one, ⁇ , v. 0, (.) (Where + and — are V, w ⁇ ⁇ , V, ⁇ are logical product, logical sum, and exclusive logical sum of V, w as bit strings, and (,) is the order of calculation. Represents parentheses for specifying.)
- Step 1402 assigns an empty set to EXP-SE.
- Step 1403 finds an array of SYM—SET characters of length 10 (but the same character may be used more than once) and assigns it to the variable EXP.
- Step 1404 determines whether EXP is significant as a mathematical expression. This determination can be realized by a parsing technique described in a compiler, Sangyo Tosho (1981), pp. 41-140. If so, go to step 1405 and add EXP to EXP—SET. If not, go to step 1406.
- Step 1406 determines whether all arrays of length 10 that can be generated from SYM-SET have been processed. If processing is completed, return. Otherwise, go to step 1407. In step 1407, a new array having a character length of 10 in the S YM SET is assigned to EXP, and the process returns to step 1404.
- the repetition pattern in the raw data is completely hidden. As a result, the encryption strength is higher.
- the third embodiment is a specific example of the sixth and seventh methods described above, and repeats the compression encryption process for data of an amount not exceeding the main storage capacity of the information processing system.
- the compression and encryption process incorporates the encryption process into adaptive Huffman compression, which is a typical compression method based on an adaptive stochastic model.
- adaptive Huffman coding will be briefly described.
- the appearance probability of the symbol is obtained by examining the frequency of the symbol in the raw data, and the correspondence between the symbol and the bit string is determined based on the probability ( After determining the Huffman tree structure), the symbols in the raw data were converted to the corresponding bit strings.
- the adaptive Huffman coding used in the present embodiment a symbol is converted into a bit string by the following steps using the expected value of the symbol appearance probability.
- the initial value and the correction method of the estimated probability of occurrence are set to the same value and method as at the time of compression, and the raw data is repeated by repeatedly converting bit strings to symbols and correcting the estimated probability of occurrence. Restore.
- FIG. 15 is a diagram showing a functional configuration of the present embodiment.
- the block 1501 and the block 1513 are complete information processing systems, and data can be sent from the block 1501 to the block 1513 by a communication line.
- Block 1502 is processing realized by the central processing unit and the input / output device.Input / output 1503, control 1504, compression 1505, encryption 1506, transmission It consists of each process of 1507.
- Block 1508 is RAM (random access memory), etc., and stores the appearance probability prediction information 1509.
- a block 1510 is a secondary storage realized by a hard disk or the like, and stores raw data 1511 and compressed encrypted data 1512.
- Block 1514 is processing realized by the central processing unit and input / output device.Input / output 1515, control 1516, reception 1517, decryption 1518, restoration It consists of the processing of 15 19.
- the block 1520 is a main memory realized by a RAM (random access memory) or the like, and stores appearance probability prediction information 1521.
- Block 1522 is a secondary storage realized by a hard disk or the like, and stores compressed encrypted data 1523 and raw data 1524.
- Input / output 1503 inputs raw data and stores it in secondary storage 15010.
- a compression encryption command and a data transmission command are input and passed to control 1504.
- the control 1504 repeats the steps of sequentially starting the compression 1505 and the encryption 1506 when receiving the compression encryption command, and compressing and encrypting a part of the raw data. Then, the entire raw data is compressed and encrypted and stored in the secondary storage 1510. At this time, the amount of raw data to be compressed and encrypted in one step is set so that the amount of memory required for processing does not exceed the main storage capacity of the information processing system 1501. Further, when the control 1504 receives the transmission command of the compressed encrypted data, the control 1504 activates the transmission 1507 and transmits the compressed encrypted data to the information processing system 1513.
- the compression 1505 compresses and encrypts a part of the raw data 15011 and passes it to the encryption 1506.
- the initial value of the symbol appearance probability prediction information 1509 is set in the main memory 1508, and the value is updated. This processing will be described later in detail with reference to FIGS. 16 and 17.
- the encryption 1506 receives the compressed data from the compression 1505, encrypts only a specified amount from the beginning, and stores it in the secondary storage 15010.
- the transmission 1507 sends the compressed encrypted data to the information processing system Send to 3.
- -Input / output 15 15 inputs the decryption restoration command and passes it to control 15 16.
- the raw data 1 5 2 4 in the secondary memory 1 5 2 2 is output.
- the control 15 16 decrypts the compressed encrypted data by repeating the steps of sequentially starting the decryption 15 18 and the recovery 15 19 and decrypting the compressed encrypted data 1 5 2 3 Then, the obtained raw data is stored in the secondary storage 1524. At this time, the amount of compressed encrypted data to be decrypted / decompressed in one step is set so that the amount of memory required for processing does not exceed the main storage capacity of the system 1513.
- the reception 15 17 receives the compressed encrypted data from the transmission 15 07 and stores it in the secondary storage 15 22.
- the decryption 1518 decrypts only the specified amount from the beginning of the compressed encrypted data by the inverse conversion of the encryption 1506, and passes it to the decryption 1519.
- the decompression 1519 decompresses the data and stores it in the secondary storage 1522.
- the initial value of the symbol appearance probability prediction information 1 5 2 1 is set in the main memory 1 5 2 0, and the value is updated. This processing will be described later in detail with reference to FIG.
- FIG. 16 shows a detailed processing method of the compression 1505.
- step 1601 conventional adaptive Huffman compression is applied to the specified number of symbols from the beginning of the raw data.
- step 1602 processed the values of 1, 0 of the Huffman tree branch by using secret parameters (called keys) common to both the compressed 1505 and the restored 1519 and so far. It changes depending on the raw data, and the result is used as initial symbol-bit string correspondence information (in the future compression and encryption processing). The details of this processing will be described later with reference to FIG.
- step 1603 other symbol-bit string correspondence information is obtained from the initial symbol-bit string correspondence information.
- the method is the same as step 102 in FIG.
- the plurality of Huffman trees obtained here are not stored individually, but by adding a plurality of 1,0 values to a single tree structure branch as described in FIG. 13. Memorize.
- step 1604 one symbol-bit string correspondence information is selected by the same method as in step 103, and is used as use correspondence information.
- Step 1605 sets the next symbol of the raw data as the current symbol.
- step 1606 the current symbol is converted into a bit string based on the usage correspondence information.
- Step 1607 determines whether or not all the raw data has been processed. If so, return; otherwise, go to step 1608.
- step 1608 the frequency of the symbol processed immediately before is increased by 1, the appearance probability prediction information of each symbol is updated accordingly, and all the symbol-bit string correspondence information is changed based on the value. .
- the structure of a single Huffman tree representing all symbol one-bit string correspondence information is changed.
- the usage correspondence information is changed to other symbol-bit string correspondence information in the same manner as in step 160.
- step 1602 the details of the generation of the initial symbol one-bit string correspondence information in step 1602 will be described.
- the values of 0 and 1 of the branches of the Huffman tree generated so far are deleted, and then the processing of FIG. 17 is applied to the root node of the Huffman tree to newly add the branches of the Huffman tree. Add a value.
- the processing in FIG. 17 is basically the same as the processing in FIG. 4 of the first embodiment, except that a value is added to the branch based on the function value h instead of the random number r. Only differ.
- Step 1 0 1 1 determines whether the node is a leaf node.
- Step 1502 2 takes as input the common secret parameter (key) and frequency of symbols counted so far for compression 1550 and decompression 1 5 19, outputs an integer value, However, the integer value h is calculated by the function f whose output changes completely if it changes.
- Such functions are described in I.I.I.I.I.I.I. Transaction on Information Theory, Vol. 30, No. 5, pp. 776-780 (IEEE Transaction on Information Theory, Vol. 30). , No. 5, pp. 776-780).
- Step 15023 determines whether h is even or odd. If it is even, go to step 1104, add 0 and 1 to the left and right branches respectively, if it is odd, go to step 101, and add 1 and 0 to the left and right branches respectively. Is added. Step 1 0 16 recursively applies this processing to the left child node. Step 1 0 17 recursively applies this process to the right child node.
- Step 1801 restores the specified number of symbols by the conventional adaptive Huffman compression restoration method.
- the specified value of the number is set equal to the specified value of the step 1601 in FIG.
- initial symbol-bit string correspondence information is generated by the same method as in step 1602.
- other initial symbol / bit string correspondence information is generated from the initial symbol / bit string correspondence information by the same method as in step 1603.
- one symbol-one bit string correspondence information is selected and used as use correspondence information by the same method as in step 1604.
- step 1805 a bit string corresponding to the symbol is cut out from the beginning of the compressed data based on the use correspondence information.
- Steps from this step to step 1808 are the same as steps 703 to 706 of the first embodiment.
- step 1809 depending on the symbol restored just before, the appearance probability prediction information of the symbol is corrected, and all the symbol-bit string correspondence information is changed based on the corrected value. As the actual calculation, the structure of one Huffman tree representing all the symbol-bit string correspondence information is changed.
- step 1810 the use correspondence information is changed to other symbol-bit string correspondence information in the same manner as in step 1609, and then the process returns to step 1805.
- the raw data can be compressed and encrypted, and the compressed and encrypted data can be decrypted and restored to restore the original raw data.
- Compression and encryption at one time so that the amount of memory required when compressing and encrypting data and the amount of memory required when decrypting and restoring data do not exceed the main storage capacity of the information processing system.
- the encryption processing is applied to the entire compressed data.
- the raw data is encrypted by applying the encryption process.
- the processing of (1) is the addition of 0 and 1 to the branches of the Huffman tree.
- the Huffman tree is a tree having leaf nodes only for the type of symbol, and the number of branches is (type of symbol—1) ⁇ 2. Since the types of symbols are at most about 300, the processing of (1) is processing to add 0 or 1 to the technique of about 600 at most, and it is possible to convert compressed data of several kilobytes to several megabytes. It can be executed in a negligible amount of time compared to the conventional process that adds complicated encryption. Similarly, the processing time of (2) is negligibly small.
- (3) is a process for encrypting the first part of the compressed data, for example, for 100 symbols, and can be ignored compared to the conventional process for encrypting the entire compressed data (usually tens of thousands to several hundred thousand symbols). It can be executed in less time.
- the decryption processing in the conventional decryption and restoration method, the decryption processing is applied to the entire compressed encrypted data.
- (1) generation of symbol one-bit string correspondence information based on function values, (2) modification of symbol one-bit string correspondence information, and (3) decryption of the leading part of compressed encrypted data Decrypts the compressed encrypted data by applying the encryption process.
- the processing time of (1) to (3) is negligibly short, as in the case of encryption. As described above, according to the present embodiment, it is possible to reduce the time required for decoding restoration. Industrial applicability
- a process of compressing and encrypting data since the process of decrypting and restoring the compressed and encrypted data can be executed in the main storage device of the information processing system, it is not necessary to read and write the intermediate result to the secondary storage device, thus improving the efficiency. Improvements and reductions in power consumption can be achieved.
- the amount of calculation in the process of compressing and encrypting data and the process of decrypting and restoring the compressed and encrypted data can be reduced, thereby improving efficiency. it can.
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Description
Claims
Priority Applications (5)
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EP95931399A EP0851627A4 (en) | 1995-09-13 | 1995-09-13 | METHOD AND DEVICE FOR COMPRESSING AND ENCRYPTING DATA |
PCT/JP1995/001815 WO1997010659A1 (fr) | 1995-09-13 | 1995-09-13 | Procede et dispositif de compression et de chiffrement de donnees |
AU34844/95A AU3484495A (en) | 1995-09-13 | 1995-09-13 | Method and device for compressing and ciphering data |
US09/029,547 US6122378A (en) | 1995-09-13 | 1995-09-13 | Data compression/encryption method and system |
US09/645,605 US6411714B1 (en) | 1995-09-13 | 2000-08-25 | Data decompression/decryption method and system |
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PCT/JP1995/001815 WO1997010659A1 (fr) | 1995-09-13 | 1995-09-13 | Procede et dispositif de compression et de chiffrement de donnees |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0889471A3 (en) * | 1997-07-03 | 1999-02-17 | AT&T Corp. | Custom character-coding compression for encoding and watermarking media content |
JP2002217887A (ja) * | 2001-01-18 | 2002-08-02 | Nec Corp | San暗号化制御方式 |
JP2008109611A (ja) * | 2006-09-29 | 2008-05-08 | Fujitsu Ltd | 暗号変換装置、暗号変換方法および暗号変換プログラム |
US8705742B2 (en) | 2006-12-26 | 2014-04-22 | Fujitsu Limited | Data compression apparatus and data decompression apparatus |
Families Citing this family (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6931451B1 (en) * | 1996-10-03 | 2005-08-16 | Gotuit Media Corp. | Systems and methods for modifying broadcast programming |
US20030093790A1 (en) | 2000-03-28 | 2003-05-15 | Logan James D. | Audio and video program recording, editing and playback systems using metadata |
US6275588B1 (en) * | 1998-11-12 | 2001-08-14 | I-Data International A/S | Apparatus and method for performing and controlling encryption/decryption for data to be transmitted on local area network |
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US20050015608A1 (en) | 2003-07-16 | 2005-01-20 | Pkware, Inc. | Method for strongly encrypting .ZIP files |
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US7047420B2 (en) | 2001-01-17 | 2006-05-16 | Microsoft Corporation | Exclusive encryption |
US20070300258A1 (en) * | 2001-01-29 | 2007-12-27 | O'connor Daniel | Methods and systems for providing media assets over a network |
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US7610627B1 (en) * | 2004-01-23 | 2009-10-27 | Acxiom Corporation | Secure data exchange technique |
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US8566616B1 (en) | 2004-09-10 | 2013-10-22 | Altera Corporation | Method and apparatus for protecting designs in SRAM-based programmable logic devices and the like |
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DE102006004693A1 (de) * | 2006-01-31 | 2007-08-09 | Siemens Ag | Navigationssystem, Verfahren und Computerprogrammprodukt zum Betreiben des Navigationssystems |
US7735101B2 (en) | 2006-03-28 | 2010-06-08 | Cisco Technology, Inc. | System allowing users to embed comments at specific points in time into media presentation |
US8769311B2 (en) | 2006-05-31 | 2014-07-01 | International Business Machines Corporation | Systems and methods for transformation of logical data objects for storage |
EP2033066A4 (en) | 2006-05-31 | 2012-08-15 | Ibm | METHOD AND SYSTEM FOR TRANSFORMING LOGIC DATA OBJECTS FOR STORAGE PURPOSES |
US8379638B2 (en) * | 2006-09-25 | 2013-02-19 | Certes Networks, Inc. | Security encapsulation of ethernet frames |
US20080082837A1 (en) * | 2006-09-29 | 2008-04-03 | Protegrity Corporation | Apparatus and method for continuous data protection in a distributed computing network |
US8225106B2 (en) | 2008-04-02 | 2012-07-17 | Protegrity Corporation | Differential encryption utilizing trust modes |
EP2337348A4 (en) * | 2008-10-15 | 2012-09-05 | Mitsubishi Electric Corp | ENCRYPTION DEVICE AND DECODING DEVICE AND ENCRYPTION METHOD AND DECODING METHOD |
US12381714B2 (en) * | 2020-01-24 | 2025-08-05 | Ariel Scientific Innovations Ltd. | Data compression and encryption algorithm |
US11366735B2 (en) | 2020-08-20 | 2022-06-21 | Bank Of America Corporation | Dynamic data storage management |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60164787A (ja) * | 1984-02-07 | 1985-08-27 | 沖電気工業株式会社 | 転置暗号方式 |
JPH0437367A (ja) * | 1990-06-01 | 1992-02-07 | Fujitsu General Ltd | データ圧縮制御方法 |
JPH04119386A (ja) * | 1990-09-10 | 1992-04-20 | Nec Corp | 暗号化コード変換方式 |
JPH04296169A (ja) * | 1991-03-26 | 1992-10-20 | Canon Inc | 画像伝送装置、画像符号化装置、画像復号装置、及びそれらの方法 |
JPH05333772A (ja) * | 1992-05-29 | 1993-12-17 | Toshiba Corp | メッセージデータ圧縮装置 |
JPH06112840A (ja) * | 1992-09-30 | 1994-04-22 | Ricoh Co Ltd | 符号化復号化方法およびその装置 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3587710T2 (de) * | 1984-10-17 | 1994-04-28 | Ericsson Ge Mobile Communicat | Teilbandkodierungsverfahren und Einrichtung. |
FR2596177B1 (fr) * | 1986-03-19 | 1992-01-17 | Infoscript | Procede et dispositif de sauvegarde qualitative de donnees numerisees |
US4937844A (en) * | 1988-11-03 | 1990-06-26 | Racal Data Communications Inc. | Modem with data compression selected constellation |
US5479512A (en) * | 1991-06-07 | 1995-12-26 | Security Dynamics Technologies, Inc. | Method and apparatus for performing concryption |
US5285497A (en) * | 1993-04-01 | 1994-02-08 | Scientific Atlanta | Methods and apparatus for scrambling and unscrambling compressed data streams |
US5802599A (en) * | 1994-02-08 | 1998-09-01 | International Business Machines Corporation | System and method for allocating storage in a fragmented storage space |
-
1995
- 1995-09-13 WO PCT/JP1995/001815 patent/WO1997010659A1/ja not_active Application Discontinuation
- 1995-09-13 EP EP95931399A patent/EP0851627A4/en not_active Withdrawn
- 1995-09-13 US US09/029,547 patent/US6122378A/en not_active Expired - Fee Related
- 1995-09-13 AU AU34844/95A patent/AU3484495A/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60164787A (ja) * | 1984-02-07 | 1985-08-27 | 沖電気工業株式会社 | 転置暗号方式 |
JPH0437367A (ja) * | 1990-06-01 | 1992-02-07 | Fujitsu General Ltd | データ圧縮制御方法 |
JPH04119386A (ja) * | 1990-09-10 | 1992-04-20 | Nec Corp | 暗号化コード変換方式 |
JPH04296169A (ja) * | 1991-03-26 | 1992-10-20 | Canon Inc | 画像伝送装置、画像符号化装置、画像復号装置、及びそれらの方法 |
JPH05333772A (ja) * | 1992-05-29 | 1993-12-17 | Toshiba Corp | メッセージデータ圧縮装置 |
JPH06112840A (ja) * | 1992-09-30 | 1994-04-22 | Ricoh Co Ltd | 符号化復号化方法およびその装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP0851627A4 * |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0889471A3 (en) * | 1997-07-03 | 1999-02-17 | AT&T Corp. | Custom character-coding compression for encoding and watermarking media content |
US6266419B1 (en) | 1997-07-03 | 2001-07-24 | At&T Corp. | Custom character-coding compression for encoding and watermarking media content |
US6760443B2 (en) | 1997-07-03 | 2004-07-06 | At&T Corp. | Custom character-coding compression for encoding and watermarking media content |
US7492902B2 (en) | 1997-07-03 | 2009-02-17 | At&T Corp. | Custom character-coding compression for encoding and watermarking media content |
US8041038B2 (en) | 1997-07-03 | 2011-10-18 | At&T Intellectual Property Ii, L.P. | System and method for decompressing and making publically available received media content |
JP2002217887A (ja) * | 2001-01-18 | 2002-08-02 | Nec Corp | San暗号化制御方式 |
JP2008109611A (ja) * | 2006-09-29 | 2008-05-08 | Fujitsu Ltd | 暗号変換装置、暗号変換方法および暗号変換プログラム |
US8713328B2 (en) | 2006-09-29 | 2014-04-29 | Fujitsu Limited | Code conversion apparatus, code conversion method, and computer product |
US8705742B2 (en) | 2006-12-26 | 2014-04-22 | Fujitsu Limited | Data compression apparatus and data decompression apparatus |
Also Published As
Publication number | Publication date |
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AU3484495A (en) | 1997-04-01 |
US6122378A (en) | 2000-09-19 |
EP0851627A4 (en) | 2000-11-22 |
EP0851627A1 (en) | 1998-07-01 |
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