Method for deriving multiple cryptographic keys from a master key in a security microprocessor

摘要

The method involves determining a derivation key function (KDF) from a permanent main key (K), a variable parameter (X) and a public or private key (S), where the key function comprises a cryptographic function controlled by the main key. A commutative operation is performed on two operands, where the operation comprises an exclusive OR operation and an AND operation. The derivation key function is calculated by selecting the variable parameter, calculating two keys using a cryptographic calculation unit of a safety microprocessor and combining the keys to produce a derived key (K').