JavaCard OS

Recently,I need to compute values using log and sqrt on a JavaCard. Is there any class for javacard to solve this issue ?
Many thanks.

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 can get it working.

horse dream wrote: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 can get it working.

Sorry to tell you I have to do all the calculation on the card side. Anyhow,thank you for your attention.

I've not came across such a class yet. The only way to meet your request is to use some limited tricks with the crypto API.

Larson wrote:I've not came across such a class yet. The only way to meet your request is to use some limited tricks with the crypto API.

Would you please give me a example ?

e.g. You can perform an RSA modulo exponentiation using 2 as public key and a large modulus to perform squares.