I was reading HMAC on wikipedia and I was confused about a few points. Where do I use HMAC? Why is the key part of the hash? Even if someone successfully used a "length-extension attack", how …

Note that HMAC is a specific scheme as Seth correctly describes; SHA-3 uses KMAC which is therefore another hash based MAC. Maybe the acronyms CBMAC and HBMAC could be used for Cipher …

The HMAC RFC (2104) lists this: We denote by B the byte-length of such blocks (B=64 for all the above mentioned examples of hash functions), and by L the byte-length of hash outputs (L=16 for MD5, …

Jan 20, 2015 · Is there anything different about how secure these two hashing algorithms are? Does HMAC "fuse" the data and the key in a special way that's more security-aware?

Apr 8, 2026 · I am working with HMAC-SHA256, where the input message is processed in 512-bit blocks. However, in my implementation, only 64 bits of the message seem to be …

Aug 5, 2015 · HMAC user-input keys that are longer than the specific hash algorithms blocksize are first shortened. (By running the long keys through the hash. And then using that hash as the actual key.) …

When people say HMAC-MD5 or HMAC-SHA1 are still secure, they mean that they're still secure as PRF and MAC. The key assumption here is that the key is unknown to the attacker.

On a recent question it became apparent that there's a significant difference between an HMAC of input data and a hash of input data. What exactly is the difference between an HMAC and a hash of ...

Oct 28, 2022 · It is an HMAC (HMAC-SHA2-256 in this case) computed using a MAC-specific key (one of two actually; client and server each have a different key they use for generating the HMAC, though …

Apr 22, 2014 · Both can be used to verify the integrity of a message. Assuming you have the needed primitives available to you (i.e. the code space of needing both a cipher and a hash function isn't …