Method and apparatus to provide authentication and privacy with low complexity devices
View Patent ↗A method and apparatus to provide a cryptographic protocol for secure authentication, privacy, and anonymity. The protocol, in one embodiment, is designed to be implemented in a small number of logic gates, executed quickly on simple devices, and provide military grade security.
1. A method of utilizing a radio-frequency identification (RFID) tag comprising:
receiving a challenge at the RFID tag from a reader;
calculating S=f(s, O E ), U=f(u, O O ), B=E(n, k E ), G=f(A, k O ), where
A is a function of the challenge and a private key of the RFID tag;
s and u are random numbers generated by the RFID tag,
n is a tag ID,
k E and k O are functions of a first public key and a second public key of the reader respectively, and
O E and O O are originators, provided by the reader; and
returning S, U, B, and G from the RFID tag to the reader, the returned data including a challenge response and the tag ID, and being unique for each response even when responding to an identical challenge.
2. The method of claim 1 , wherein the originators O E and O O are points on an elliptical curve.
3. The method of claim 1 , wherein the originators O E and O O are generators for large primes.
4. The method of claim 1 , further comprising initializing the RFID tag, wherein the initialization comprises receiving from the reader:
the first public key of a first key pair for privacy;
the second public key of a second key pair for obfuscation; and
the tag ID.
5. The method of claim 4 , wherein the initialization further comprises:
selecting a third key pair for authentication; and
sending a public key of the third key pair to the reader.
6. The method of claim 4 , wherein initialization further comprises:
receiving from the reader a private key of a third key pair for authentication, the private key of the third key pair stored only by the RFID tag.
7. A low processing power system (LPPS) comprising:
a transceiver configured to transmit and receive data, the transceiver further configured to receive a challenge from a reader system;
a crypto logic configured to perform cryptographic calculations, the crypto logic configured for calculating S=f(s, O E ), U=f(u, O O ), B=E(n, k E ), G=f(A, k O ), where
A is a function of the challenge and a private key of the LPPS,
s and u are random numbers generated by the LPPS,
n is an identifier of the LPPS,
k E and k O are functions of a first public key and a second public key of the reader respectively, and
O E and O O are originators, provided by the reader;
the transceiver further configured to return S, U, B, and G to the reader system, the returned data including a challenge response and the identifier of the LPPS, and being unique for each response even when responding to an identical challenge.
8. The system of claim 7 , further comprising a secured memory to store the private key of the LPPS and the identifier of the LPPS.
9. The system of claim 7 , wherein the crypto logic is further configured for generating the random numbers s and u.
10. The system of claim 7 , further comprising:
a memory to store initialization data, the initialization data including the public keys of the reader, and the identifier of the LPPS.
11. The system 7 , wherein the originators O E and O O are points on an elliptical curve, and wherein originators O E and O O are the same point on the same elliptical curve.