Search found 73 matches

by BirdKing
Fri Jan 19, 2018 1:47 am
Forum: Algorithm School
Topic: How to compute MAC
Replies: 13
Views: 4517

Re: How to compute MAC

According to GPC_Specification_v2.2.1, the ICV should be the MAC of the EXTERNAL AUTHENTICATE command. The description from GPC_Specification_v2.2.1 is : E.3.2 Message Integrity ICV using Explicit Secure Channel Initiation When using explicit Secure Channel initiation, SCP02 mandates the use of a MA...
by BirdKing
Tue Apr 19, 2016 5:51 am
Forum: Other Tools
Topic: I want a tool to get bytecode speed time
Replies: 4
Views: 2096

I want a tool to get bytecode speed time

hello,
I want a tool to get bytecode speed time oncard. Could you help me?
by BirdKing
Tue Apr 19, 2016 5:49 am
Forum: Communication
Topic: How anderstance SFGT?
Replies: 1
Views: 1457

How anderstance SFGT?

hello,
I 'm in a puzzle about the SFGT.
In 14443, what role the SFGT acts ?
by BirdKing
Tue Apr 19, 2016 1:35 am
Forum: Communication
Topic: How to implement T=CL protocol
Replies: 4
Views: 1924

Re: How to implement T=CL protocol

T=CL is block protocol, T= 1 is block protocol too. So, they are similar. You could referce to your T1 protocol implementation.
by BirdKing
Sun Dec 06, 2015 9:49 pm
Forum: Algorithm School
Topic: how compute Phi(N) of RSA?
Replies: 2
Views: 827

Re: how compute Phi(N) of RSA?

Hello,
Thank you very much.
I solved the problem following your method. :lol: :lol: :lol:
by BirdKing
Tue Nov 24, 2015 9:35 pm
Forum: Algorithm School
Topic: how compute Phi(N) of RSA?
Replies: 2
Views: 827

how compute Phi(N) of RSA?

hello, I have a problem about RSA. Please help me!
IN RSA,
N=P*Q
Phi(N) = (P-1)*(Q-1)

When compute standard RSA, a necessary condition is D<Phi(N).
Phi(N) = (P-1)*(Q-1) = P*Q - (P+Q) + 1
according N = P*Q, P + Q ≈ 2*(N^½)
Phi(N) = N - 2*(N^½) + 1

The problem is how to compute N^½
by BirdKing
Tue Nov 24, 2015 9:28 pm
Forum: Algorithm School
Topic: Error sw 6F00 when using ECDSA to implement the signing code
Replies: 1
Views: 765

Re: Error sw 6F00 when using ECDSA to implement the signing code

your construction function is private.....
by BirdKing
Tue Nov 17, 2015 4:34 am
Forum: Algorithm School
Topic: how to define total length of ECC F2M 571bits signture
Replies: 5
Views: 1358

Re: how to define total length of ECC F2M 571bits signture

Thank you for your help.
I finally understood how to struct the R and S. Following the TLV, I can get the right signature.
Thank everybody.
by BirdKing
Fri Nov 06, 2015 12:31 am
Forum: Algorithm School
Topic: Why length of R is 168bits in ECC FP 160?
Replies: 1
Views: 665

Why length of R is 168bits in ECC FP 160?

hello,
Lately, I tested ECC. When I generated a ecc keypair of 160bits, I found the length R is 168bits. That made me very doubt.
Why length of R is 168bits while ecc key length is 160bits?
by BirdKing
Fri Nov 06, 2015 12:22 am
Forum: Algorithm School
Topic: how to define total length of ECC F2M 571bits signture
Replies: 5
Views: 1358

Re: how to define total length of ECC F2M 571bits signture

UNKNwYSHSA wrote:Have you tried to calculate the signature of this bits length using openssl?

yes. I got a signature such as "30 81 94 02 ...".
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