CN110233731A - A kind of RFID safety authentication based on PUF - Google Patents

Abstract

The invention discloses a PUF-based RFID security authentication method. Firstly, a unique challenge-response pair is generated based on a PUF circuit and combined with TRNG and binary operations to form a data interaction protocol between a specified response device and a reader; and simultaneously Obtain the PUF soft model based on the verification times N, trusted ID and other parameters before the responding device and reader are deployed, and predict the output of the PUF circuit based on the PUF soft model; finally, the responding device uses TRNG to form a predetermined number of challenges, and according to The counting N table, trusted ID table, Hamming distance, tolerance level value, etc. set in the background server perform polling operations set between the response device and the reader to realize the security authentication operation of RFID; the present invention can Effectively resist malicious relay attacks during the interaction process, and can perform safe and reliable RFID authentication without increasing costs.

Description

A PUF-based RFID security authentication method

technical field

The invention belongs to the technical field of Internet of Things security, and specifically relates to an RFID (Radio Frequency Identification, radio frequency identification technology) security authentication method based on PUF (Physical Unclonable Function, physical unclonable technology). The characteristics of it solve the relay attack in RFID application.

Background technique

The Internet of Things (IoT, Internet of Things) has always been considered as the third wave of the development of the world's information industry after computers and the Internet, because it will completely change the way people live, work, entertain and travel, and even change the relationship between global governments and enterprises. interaction between. At present, the Internet of Things is showing a rapid growth momentum in the world. According to many Internet of Things authorities, we will enter a new world of Internet of Everything. It is estimated that by 2020, there will be 34 billion devices connected to the Internet. Compared with the mobile Internet of Things, the market size of the Internet of Things is dozens of times its capacity, and it can bring tens of trillions of economic value to the world. It is also regarded as a new engine for global economic growth and opens the pace of a new era.

The initial concept of the Internet of Things was first proposed by Professor Ashton of MITAuto-First ID Center when he was researching RFID in 1999: through radio frequency identification, infrared sensors, global positioning systems, laser scanners and other information sensing equipment, according to the agreed protocol, the Any item is connected to the Internet for information exchange and communication to realize a network concept of intelligent identification, positioning, monitoring and management. In the report of the same name released by the International Telecommunication Union (ITU) in 2005, the definition and scope of the Internet of Things have changed, and the coverage has also been greatly expanded. It no longer refers to the Internet of Things based on RFID technology, but has transformed into any The interconnection between any time, any place, any object, the ubiquitous network and the development vision of omniscient computing.

The construction of the Internet of Things is booming, and the application of sensing devices is becoming more and more mature. Sensing devices such as two-dimensional barcodes, RFID products, sensors, and cameras can be seen everywhere. to balance security. Governments, enterprises, and scientific research institutions are paying more and more attention to the security of the Internet of Things. There are some technical means for the security protection of sensing equipment, including high-intensity encrypted CPU cards, authentication of RFID tags, key management mechanisms, and anti- Power consumption/electromagnetic radiation analysis, fault injection attack techniques, etc. It can be seen that on the one hand, these safety protection measures have a certain protective effect, but whether they meet the relevant standards needs to be further clarified. On the other hand, some of the above-mentioned security measures are often passive defenses. In the face of new forms of IoT applications and new attacks on IoT devices, it is necessary to turn passive into active in the design, implementation, and operation stages of sensing devices, and actively develop the sensing layer. Security detection enhances the active security assurance capability of the Internet of Things.

Establishing reliable secure communication in RFID systems has been an ongoing problem due to high constraints on power consumption, implementation area, and equipment cost. Standard encryption solutions that provide provable security have prohibitive area and power requirements for RFID and other highly constrained devices. For example, low-cost RFID tags can only use 3-5k logic gates to implement security functions, while reliable and secure public cryptographic algorithm implementations for authentication can use 12k to 22k logic gates.

Contents of the invention

Aiming at the limitations of power consumption, implementation area and equipment cost in the above-mentioned prior art, the present invention provides a PUF-based RFID security authentication method; the method does not use an encryption function or a hash function, and is based on a PUF circuit, a true random The authentication process of the protocol is completed by using a digital generator and binary operations, making it a lightweight RFID security authentication protocol that can resist relay attacks and has high security and reliability without investing too much cost . Specifically, the following technical solutions are adopted:

A PUF-based RFID security authentication method, said method comprising:

Registration phase: poll the PUF and model the attack to generate a PUF soft model;

Protocol construction: use the PUF circuit to generate random and unique challenge-response pairs, and use the challenge-response pairs as the secret key in the process of implementing the protocol. The secret key is combined with TRNG and specified binary operations to form a reliable and secure The protocol that really matches the encryption algorithm in terms of aspects;

Identity authentication: a. Use TRNG (True Random Number Generation, true random number generator) to generate a vector set C consisting of m challenges _ci in the response device, and the response device will store the first number of verification times N, the second An ID and the vector set C are sent to the reader;

b. Compare the count N table in the background database of the first number of verification times N, compare the first ID with the trusted ID table in the background database, and record the number of times the reader receives the vector set C The first duration t, compare the first duration t with the allowable duration t' set in the background database, if the first verification times N is the same as the data in the count N table, and the first ID It is the same as the data in the trusted ID table, and the first duration t is less than the allowed duration t′, then receive the PUF soft model to generate a response vector _{ri for each challenge ci ,} and construct Response vector set R;

c. Using TRNG to generate a challenge vector _ci1 and a challenge vector _ci2 for each of the response vectors ri, and form a corresponding challenge vector set C′; wherein, the challenge vector _ci1 and the challenge _{vector ci2} The XOR result corresponds to the response vector r _i ;

d. Set the threshold τ, check whether the Hamming distance between the challenge vector c _i1 and the challenge vector c _i2 is within the threshold τ, and if so, send the challenge vector set C' to The responding device, otherwise, discards the challenge vector c _i1 and the challenge vector c _i2 ;

e. Set the tolerance level value α, and verify the XOR result of each of the challenge vector c _i1 and the challenge vector c _i2 received by the responding device in the challenge vector set C′, if the XOR result Within the tolerance level value, check whether the Hamming distance between the challenge _{ci , the challenge vector ci1 and} the challenge vector _ci2 is within the threshold τ, if not, then discarding the challenge vector c _i1 and the challenge vector c _i2 ;

f. The responding device sends again the challenge vector set B composed of challenge b _i to the reader, and the reader accepts the challenge vector set B and verifies the challenge token transmitted corresponding to the challenge vector set B response, and repeat steps a to e, that is, to judge the Hamming distance between the challenge vector b _i1 and the challenge vector b _i2 generated by TRNG correspondingly after the challenge _bi is sent to the reader, and the response device Whether the second number of verification times N and the second ID sent to the reader and the second duration t are consistent with the count N table, the trusted ID table and the allowed duration t', or are set If it is within the specified tolerance level, effective RFID security certification is completed.

The method also includes that the PUF utilizes the CMOS device to make inherent randomness in the protocol implementation process.

Preferably, in the protocol, the reader is combined with the background server to form a server end.

Preferably, in said protocol, each of said challenges _ci can respond to "0" or "1".

Preferably, after executing the protocol m times, the probability of randomly guessing all is 2 ^−m .

Advantageously, each said challenge has the same bit width as a challenge in said challenge-response pair in said protocol.

The RFID security authentication method based on PUF of the present invention, at first, establishes the agreement of encryption intensity security through binary operation, PUF circuit and TRNG; Then, based on the characteristic of PUF circuit, generate challenge-response pair, and use challenge-response pair as secret key; finally, based on the established protocol, the interaction between the responding device and the reader is polled. If the polling does not conform to the protocol, no interactive operation is performed, which greatly improves the security and reliability of the entire RFID communication system. Compared with the prior art, the present invention has the following beneficial effects: the protocol of the present invention provides mutual identity authentication between the server and the response device and resistance to modeling attacks, and avoids the use of encryption algorithms and unauthorized access to The polling of devices and servers can effectively resist malicious relay attacks and has good security; the present invention deploys response devices and servers before deployment, obtains legal identities and PUF soft models, and The identities of both parties are authenticated to ensure that the identities of both parties are legal and have good integrity; the present invention utilizes the unique challenge-response pairs generated by the PUF circuit and a simple binary algorithm to form a safe and reliable RFID authentication protocol.

Description of drawings

Fig. 1 is a schematic diagram of the authentication protocol of the challenge-response pair based on PUF in the embodiment of the present invention.

Fig. 2 is a schematic diagram of the execution flow of the PUF-based RFID security authentication protocol described in the embodiment of the present invention.

Figure 3 is a schematic diagram of all possible exposed challenge-response pairs during the authentication protocol process in the embodiment of the present invention.

Figure 4 is a schematic diagram of the basic flow chart of the implementation of the relay attack.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

In the embodiment of the present invention, a PUF-based RFID security authentication method is provided, wherein, PUF is an emerging hardware security primitive, which can provide a security solution for limited equipment such as RFID; PUF utilizes a CMOS device manufacturing process The inherent randomness in , producing a unique "response" when provided with a "challenge" input, makes it ideal for building secure challenge-response protocols. Based on this, the method of the present invention specifically comprises the steps:

Combined with Figure 1, the diagram shows a challenge-response pair authentication protocol based on PUF. It can be seen that when using PUF authentication, firstly, the PUF soft model is generated by polling PUF and modeling attacks to complete the initial registration operation; , the server side that has access to the soft model of the PUF will generate the challenge and send it to the device. The device will use its PUF circuit to generate responses to the challenges it receives and send them back to the server side. Then, the server side compares the response returned by the device with the response stored or generated, and if the response is within a certain Hamming distance set, it is considered authentic; and uses the set tolerance level value as the PUF Non-negligible error rate.

But in practice, because the attacker will be able to perform a relay attack by collecting the transmitted challenge-response pairs; and if encryption or hash functions are used to hide the challenge-response pairs, it needs to invest too much cost, based on Therefore, the present invention builds the protocol shown in Figure 2, in this protocol, it is assumed that the wired transmission between the background database and the reader is safe, and the wireless transmission between the reader and the response device is unsafe, so In this agreement, the background database and reader are collectively referred to as the server. Some parameters involved in this protocol are: trusted ID, count N of verification times stored by the responding device, specified Hamming distance, tolerance level value, trusted ID' stored on the background database side, count of verification times, communication The time period t for both parties to receive the verification information sent by the other party, the allowable time period of the trusted range, the response to the challenge generated by the device side, the response generated by the reader side, and the generated challenge. The function expressions involved are: TRNG(): the random number generated by the true random number generator, the character length is the same as the response command character length generated by the PUF; PUF(x): generated by the PUF device for the input challenge x response; HD(x, y): Hamming distance between x and y; XOR operation of x and y.

In actual operation, the present invention uses the PUF circuit to generate random and unique challenge-response pairs, and uses the challenge-response pair as the secret key in the protocol implementation process. The secret key is combined with TRNG and specified binary operations to form a reliable and secure Protocol that matches the encryption algorithm. Among them, before the protocol is deployed, the background database stores a trusted ID table, a verification times count N table for each ID, a related information table for each ID, and a large number of challenge-response pairs for each PUF entity. The specific implementation of the present invention through identity authentication to the defense process of the relay attack is as follows:

First, when the responding device is close to the electromagnetic field signal of the reader, it uses _TRNG to generate a vector set C consisting of m challenges ci in the responding device, where the bit width of each challenge _ci is the same as the challenge-response pair in the protocol The bit width of the challenge is the same; the responding device sends the stored first number of verifications N, the first ID and vector set C to the reader; the reader receives the first number of verifications N, the first ID and After the vector set C, compare the count N table in the background database with the first number of verification times N, compare the first ID with the trusted ID table in the background database, and record the first duration t for the reader to receive the vector set C, and set the first ID to the trusted ID table in the background database. A time length t is compared with the allowable time length t' set in the background database, if the first verification times N is the same as the data in the count N table, and the first ID is the same as the data in the trusted ID table, and the first time length t is less than Allow time t′, then receive PUF soft model to generate response vector _ri for each challenge _ci , and construct response vector set R.

Then, the reader uses TRNG to generate a challenge vector _ci1 and a challenge vector _ci2 for each response vector ri, and constitutes a corresponding challenge vector set C′; and ensures that the _XOR results of the challenge vector _ci1 and the challenge vector _ci2 correspond to Response vector r _i ; at the same time, set the threshold τ, check whether the Hamming distance between the challenge vector _ci1 and the challenge vector _ci2 is within the threshold τ, if so, send the challenge vector set C′ to the responding device, Otherwise, discarding the challenge vector c _i1 and the challenge vector c _i2 ; and setting a tolerance level value α, verifying the XOR result of each challenge vector c _i1 and challenge vector c _i2 of the challenge vector set C′ received by the responding device, If the XOR result is within the tolerance level value α, then check whether the Hamming distance between the challenge _{ci , the challenge vector ci1 and} the challenge vector _ci2 is within the threshold τ, if not, discard the challenge vector _ci1 and challenge vector c _i2 .

Finally, the response device sends the challenge vector set B composed of challenge b _i to the reader again, and the reader accepts the challenge vector set B and verifies the response corresponding to the challenge token transmitted by the challenge vector set B, and repeats the above reader and The identity authentication step between the responding devices is to judge the Hamming distance between the challenge vector b _i1 and the challenge vector b _i2 generated by using TRNG after the challenge b _i is sent to the reader, and the second challenge vector b i2 sent by the responding device to the reader Verify whether the number of times N and the second ID and the second time length t are consistent with the count N table, the trusted ID table and the allowable time length t' or whether they are within the set tolerance level value, then complete effective RFID security certification; This ensures that the responding device can only be polled by an authentic party, the same process that the server uses to generate its authentication challenge.

It should be noted that PUF in the present invention utilizes the inherent randomness in the implementation process of the COMS device manufacturing protocol; and in the protocol, the server end is formed by the combination of the reader and the background server.

During the actual execution of the protocol, each challenge c _i can respond with "0" or "1". And after executing the protocol m times, the probability of guessing all of them randomly is 2 ^-m .

Combined with Figure 4, it should be noted that in actual operation, Reader and Tag are legal readers and trusted tags respectively. Attacker A listens to the rebroadcast request verification information from the legitimate reader and sends it to attacker B. Attacker B sends the real verification information to the trusted tag. The trusted tag generates verification information for the requested verification information and sends it to attacker B. , the attacker B forwards the verification information to the attacker A, and the attacker A uses the real verification information to trick the legitimate reader into passing the verification. The entire attack is based on the assumption that both parties in the legal communication believe that they are communicating with each other at a safe distance. In fact, due to the intervention of the attacker, the legitimate user will think that the attackers A and B communicating with him are legitimate devices, which ultimately prolongs the Its communication distance, and obtain all the data in the communication.

Specifically, during the execution of the protocol, if an attacker attempts to relay attacks on the device, both the reader and the trusted device use TRNG and PUF circuits to generate verification information, which greatly increases the difficulty of forging or rebroadcasting verification information. At the same time, since the reader and the trusted tag perform effective verification every time, the number of verification times will be dynamically updated, and both parties in the communication of the protocol will verify whether the communication time is within the allowable range of the trusted distance. If the attacker uses the relay attack Rebroadcasting the verification information by the device will inevitably lead to an extension of the time. Once the communication time exceeds the allowable range, the communication parties will directly refuse the communication. It can be seen that the method of the present invention can effectively defend against relay attacks.

The RFID security authentication method based on PUF of the present invention, at first, establishes the agreement of encryption intensity security through binary operation, PUF circuit and TRNG; Then, based on the characteristic of PUF circuit, generate challenge-response pair, and use challenge-response pair as secret key; finally, based on the established protocol, the interaction between the responding device and the reader is polled. If the polling does not conform to the protocol, no interactive operation is performed, which greatly improves the security and reliability of the entire RFID communication system. Compared with the prior art, the present invention has the following beneficial effects: the protocol of the present invention provides mutual identity authentication between the server and the response device and resistance to modeling attacks, and avoids the use of encryption algorithms and unauthorized access to The polling of devices and servers can effectively resist malicious relay attacks and has good security; the present invention deploys response devices and servers before deployment, obtains legal identities and PUF soft models, and The identities of both parties are authenticated to ensure that the identities of both parties are legal and have good integrity; the present invention utilizes the unique challenge-response pairs generated by the PUF circuit and a simple binary algorithm to form a safe and reliable RFID authentication protocol.

The above are only preferred embodiments of the present invention, but do not limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still possible for those skilled in the art to understand the specific aspects of the foregoing. The technical solutions described in the implementation modes shall be modified, or some of the technical features shall be replaced equivalently. All equivalent structures made using the contents of the description and drawings of the present invention, directly or indirectly used in other related technical fields, are all within the protection scope of the patent of the present invention.

Claims (6)

1. a PUF-based RFID security authentication method, is characterized in that, described method comprises: Registration phase: poll the PUF and model the attack to generate a PUF soft model; Protocol construction: use the PUF circuit to generate random and unique challenge-response pairs, and use the challenge-response pairs as the secret key in the process of implementing the protocol. The secret key is combined with TRNG and specified binary operations to form a reliable and secure The protocol that really matches the encryption algorithm in terms of aspects; Identity authentication: a. Use _TRNG to generate a vector set C consisting of m challenges ci in the responding device, and the responding device sends the stored first number of verification times N, the first ID, and the vector set C to the reader ; b. Compare the count N table in the background database of the first number of verification times N, compare the first ID with the trusted ID table in the background database, and record the number of times the reader receives the vector set C The first duration t, compare the first duration t with the allowable duration t' set in the background database, if the first verification times N is the same as the data in the count N table, and the first ID It is the same as the data in the trusted ID table, and the first duration t is less than the allowed duration t′, then receive the PUF soft model to generate a response vector _{ri for each challenge ci ,} and construct Response vector set R; c. Using TRNG to generate a challenge vector _ci1 and a challenge vector _ci2 for each of the response vectors ri, and form a corresponding challenge vector set C′; wherein, the challenge vector _ci1 and the challenge _{vector ci2} The XOR result corresponds to the response vector r _i ; d. Set the threshold τ, check whether the Hamming distance between the challenge vector c _i1 and the challenge vector c _i2 is within the threshold τ, and if so, send the challenge vector set C' to The responding device, otherwise, discards the challenge vector c _i1 and the challenge vector c _i2 ; e. Set the tolerance level value α, and verify the XOR result of each of the challenge vector c _i1 and the challenge vector c _i2 received by the responding device in the challenge vector set C′, if the XOR result Within the tolerance level value, check whether the Hamming distance between the challenge _{ci , the challenge vector ci1 and} the challenge vector _ci2 is within the threshold τ, if not, then discarding the challenge vector c _i1 and the challenge vector c _i2 ; f. The responding device sends again the challenge vector set B composed of challenge b _i to the reader, and the reader accepts the challenge vector set B and verifies the challenge token transmitted corresponding to the challenge vector set B response, and repeat steps a to e, that is, to judge the Hamming distance between the challenge vector b _i1 and the challenge vector b _i2 generated by TRNG correspondingly after the challenge _bi is sent to the reader, and the response device Whether the second number of verification times N and the second ID sent to the reader and the second duration t are consistent with the count N table, the trusted ID table and the allowed duration t', or are set Within the specified tolerance level, effective RFID security certification is completed. 2. The RFID security authentication method based on PUF as claimed in claim 1, is characterized in that, described method also comprises, PUF utilizes CMOS device to make the randomness of secret key in the implementation process of described agreement. 3. The PUF-based RFID security authentication method according to claim 1, characterized in that, in the protocol, the reader is combined with the background server to form a server end. 4. The PUF-based RFID security authentication method according to claim 3, characterized in that, in the protocol, each challenge c _i can respond to "0" or "1". 5. The PUF-based RFID security authentication method according to claim 1, characterized in that, after performing m times of the protocol, the random guessing is all correct, that is, the probability of successful attack is 2- ^m . 6. The PUF-based RFID security authentication method according to claim 1, wherein the bit width of each challenge is identical to the bit width of the challenge in the challenge-response pair in the protocol.