Tag
message-authentication
- Apr 10, 2026 Why HMAC Hashes Twice and What Length Extension Has to Do With It The nested construction that turns a plain hash into a keyed MAC, the Merkle-Damgard weakness it neutralises, and why the two fixed inner and outer pads are load-bearing. cryptography
- Feb 12, 2026 The Verification Split: Why a MAC Cannot Settle a Dispute Symmetric tags and public-key signatures differ in who is able to check them, and that single difference determines what each can be used as evidence for. cryptography
- Nov 2, 2024 CBC-MAC Ends at the Last Block, and That Is the Problem Chaining a block cipher over a message authenticates only the final block, so variable-length messages invite splicing attacks; CMAC adds two derived subkeys to close the hole. cryptography
- Feb 17, 2023 Poly1305 and the Arithmetic of a One-Time Key A 130-bit prime, a clamped scalar, and a carry structure that make a fast MAC provably secure only when each key is used exactly once. cryptography