Section 7.3 of SP 800-108:

To comply with this Recommendation, the derived keying material shall not be used as a key stream for a stream cipher.


The level of security provided by using the key derivation functions specified in this Recommendation to generate a key stream for stream ciphers has not been investigated.

I was wondering why the derived keying material can be cut into valid cryptographic keys but cannot be used for stream cipher. Since it is marked as a shall not, are there any serious concerns if the derived keying material is used for stream cipher (other than it may not be long enough for given plaintext)?


Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.