I want to implement AES algorithm,instead of 128 bit key encryption I wanted to do it for 256.But I’m stuck at point creating scheduling for 256 key generation. Can anyone help in this.

  • 1
    $\begingroup$ Er, you realise that AES keys can only be 128, 192 or 256 bits? There's no AES-512. $\endgroup$
    – Paul Uszak
    Jun 19, 2018 at 11:40
  • 3
    $\begingroup$ If you need to know how to handle 256 bit keys, well, section 5.2 of FIPS 197 is a start (with Appendix A giving a real test vector, useful for finding misunderstandings). Is there anything specific about that you don't understand? $\endgroup$
    – poncho
    Jun 19, 2018 at 12:39

1 Answer 1


I agree with @poncho, you have to read FIPS 197 (https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.197.pdf). You should look on paragraph 5.2 Key Expansion. This one have a pseudo code. Also you can look on implementation in Go's runtime (https://github.com/golang/go/blob/master/src/crypto/aes/block.go).


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.