One way authentication
View Patent ↗A cryptosystem prevents replay attacks within existing authentication protocols, susceptible to such attacks but containing a random component, without requiring modification to said protocols. The entity charged with authentication maintains a list of previously used bit patterns, extracted from a portion of the authentication message connected to the random component. If the bit pattern has been seen before, the message is rejected; if the bit pattern has not been seen before, the bit pattern is added to the stored list and the message is accepted.
1. A method for a correspondent confirming originality and authenticity of a signed message generated and signed by another correspondent, the method comprising:
said correspondent receiving from said other correspondent said signed message, said signed message comprising information I, and a signature comprising a first signature component r, and a second signature component s;
a cryptographic processor of said correspondent:
computing an ephemeral public key kP using said information I, said first signature component r, said second signature component s, and a long term public key A of said other correspondent;
converting a first co-ordinate of kP into an integer;
comparing said integer with said first signature component r;
obtaining a subset f(r) from said first signature component r;
comparing said subset f(r) with a list of subsets previously stored by said correspondent; and,
verifying said signature and accepting said verification when said integer matches said first signature component r and said subset f(r) is not in the list.
2. The method of claim 1 wherein obtaining comprises extracting.
3. The method of claim 1 wherein obtaining comprises deriving.
4. The method according to claim 1 wherein said previously stored list of subsets is maintained in a database of one of said correspondents.
5. The method according claim 4 wherein when said obtained subset is not matched to said previously stored list of subsets, said method further comprises said correspondent adding said obtained subset to said database.
6. The method according to claim 1 wherein said previously stored list of subsets comprises bit patterns obtained from other correspondents.
7. The method according to claim 1 wherein said signature computed by said other correspondent comprises a result of a ECDSA signature operation performed by solving a signing equation ks=H(I)+dr(mod n), where d is a long term private key of said correspondent.
8. A computing device correspondent comprising a processor and a memory, said computing device being connectable to a data communication system, and being configured to:
receive a signed message generated and signed by another correspondent, said signed message comprising information I, and a signature comprising a first signature component r, and a second signature component s;
compute an ephemeral public key kP using said information I, said first signature component r, said second signature component s, and a long term public key A of said other correspondent;
convert a first co-ordinate of kP into an integer;
compare said integer with said first signature component r;
obtain a subset f(r) from said first signature component r;
compare said subset f(r) with a list of subsets previously stored by said correspondent; and,
verify said signature and accept said verification when said integer matches said first signature component r and said subset f(r)is not in the list, to confirm an originality and authenticity of said signed message.
9. The computing device correspondent of claim 8 wherein to obtain comprises to extract.
10. The computing device correspondent of claim 8 wherein to obtain comprises to derive.
11. The computing device correspondent of claim 8 wherein said previously stored list of subsets is maintained in a database of one of said correspondents.
12. The computing device correspondent of claim 11 wherein when said obtained subset is not matched to said previously stored list of subsets, and said computing device is further operative to add said obtained subset to said database.
13. The computing device correspondent of claim 8 wherein said previously stored list of subsets comprises bit patterns obtained from other correspondents.
14. The computing device correspondent of claim 8 wherein said signature computed by said other correspondent comprises a result of a ECDSA signature operation performed by solving a signing equation ks=H(I)+dr(mod n), where d is a long term private key of said correspondent.
15. A non-transitory computer readable memory having recorded thereon instructions for execution by a computing device to render the computing device operative to:
receive a signed message generated and signed by another correspondent, said signed message comprising information I, and a signature comprising a first signature component r, and a second signature component s;
compute an ephemeral public key kP using said information I, said first signature component r, said second signature component s, and a long term public key A of said other correspondent;
convert a first co-ordinate of kP into an integer;
compare said integer with said first signature component r;
obtain a subset f(r) from said first signature component r;
compare said subset f(r) with a list of subsets previously stored by said correspondent; and,
verify said signature and accept said verification when said integer matches said first signature component r and said subset f(r) is not in the list, to confirm an originality and authenticity of said signed message.
16. The non-transitory computer readable medium of claim 15 wherein to obtain comprises to extract.
17. The non-transitory computer readable medium of claim 15 wherein to obtain comprises to derive.
18. The non-transitory computer readable medium of claim 15 wherein said previously stored list of subsets is maintained in a database of one of said correspondents.
19. The non-transitory computer readable medium of claim 18 wherein when said obtained subset is not matched to said previously stored list of subsets, and wherein said computing device is further operative to add said obtained subset to said database.
20. The non-transitory computer readable medium of claim 15 , wherein said previously stored list of subsets comprises bit patterns obtained from other correspondents.
21. The non-transitory computer readable medium of claim 15 , wherein said signature computed by said other correspondent comprises a result of a ECDSA signature operation performed by solving a signing equation ks=H(I)+dr(mod n), where d is a long term private key of said correspondent.