Tag
finite-fields
- Oct 12, 2026 Constructing an S-Box: Field Inversion and Differential Uniformity Why the AES substitution table is an inverse map in GF(2^8) followed by an affine transform, and how differential uniformity bounds the best characteristic. cryptography
- Oct 6, 2025 GHASH and the Structure of a GCM Tag Why the authenticator is a polynomial evaluation in a binary field rather than a chained MAC, how the length block prevents padding ambiguity, and what tag truncation costs in forgery probability. cryptography
- May 19, 2025 Recovering the GCM Authentication Key from a Repeated Nonce Two messages encrypted under the same GCM nonce turn the tag difference into a polynomial in the hash subkey, whose roots yield the key and permit arbitrary forgery. cryptography
- Aug 9, 2023 The AES State Matrix: Byte Ordering, ShiftRows, and MixColumns How sixteen key bytes map onto a four-by-four matrix, why the row shift moves different distances, and what MixColumns does to a column as a polynomial. cryptography