Search found 76 matches
- Tue Jun 16, 2015 1:54 am
- Forum: Algorithm School
- Topic: Find a faster way to compute CMAC subkeys
- Replies: 2
- Views: 7835
Re: Find a faster way to compute CMAC subkeys
Maybe you can try hard coding by loop unrolling . Remember to creat RAM byte array. output[0] = (byte)((byte)(input[0] << 1) | (byte)((input[1] >> 7) & 1)); output[1] = (byte)((byte)(input[1] << 1) | (byte)((input[2] >> 7) & 1)); output[2] = (byte)((byte)(input[2] << 1) | (byte)((input[3] >...
- Thu Jun 11, 2015 4:14 am
- Forum: Questions & Answers
- Topic: Store a String data in JavaCard
- Replies: 1
- Views: 7191
Re: Store a String data in JavaCard
String data can be represented as byte array. Creat byte array first, and then initialize array.
e.g.
PS: The above code only works fine within the ASCII range of characters.
e.g.
Code: Select all
byte string[];
string = {'h', 'e', 'l', 'l', 'o'};
PS: The above code only works fine within the ASCII range of characters.
- Wed Jun 10, 2015 7:43 am
- Forum: Algorithm School
- Topic: How to compute values using ' log' and 'sqrt' on javacard ?
- Replies: 5
- Views: 11511
Re: How to compute values using ' log'?
Javacard doesn't support Math class and also only supports boolean, byte, short, and optionally int. Maybe you can create your own class with tricky ways and of course the result is not precise. If you let server/terminal side do complex calculation/encryption, the card only stores data,maybe you ca...
- Fri Jun 05, 2015 3:33 am
- Forum: Algorithm School
- Topic: Generate random number
- Replies: 1
- Views: 5822
Re: Generate random number
The following is a simple code that you can refer to. Hope to help you. BTW, if you have anyother questions ,feel free to post them here. package nl.owlstead.jcsecurerandom; import javacard.framework.JCSystem; import javacard.framework.Util; import javacard.security.RandomData; public final class JC...
- Fri May 22, 2015 1:53 am
- Forum: Communication
- Topic: ISO7816 - Odd INS codes?
- Replies: 4
- Views: 11537
Re: ISO7816 - Odd INS codes?
Hi,horse dream.Could you please explain what you mean : "Odd instruction codes are typically handled differently from the even ones by the card, they are no simple aliases for these..." As we all know,according to ISO, odd INS codes are invalid . What I want to know is if there is a card,...
- Fri May 22, 2015 1:14 am
- Forum: Communication
- Topic: ISO7816 - Odd INS codes?
- Replies: 4
- Views: 11537
Re: ISO7816 - Odd INS codes?
The specification that you saw is an old version. Odd instruction codes are typically handled differently from the even ones by the card, they are no simple aliases for these, but equally valid. Beaucse 7816-4 requires a different handling of secure messaging and the pressure towards odd instruction...