A method of diversifying a key base and to authenticate one like diversified key as having been prepared starting from a predetermined key base, and a system for carrying out the process.

摘要

THE invention is a process for basic and diversify a KEY to authenticate such a key DIVERSIFIED BEEN PREPARED AS IF FROM A BASIC KEY DEFAULT. INITIALIZATION SYSTEM KEY Calculates a DIVERSIFIED (SD) KEY FROM A BASIC (SB) TREATED BY COMBINING TRANSFORMATION-one (T). THE KEY (SD) recorded in the memory (M3) of a user card (CU3) IS authenticated by an operating system (4) CALCULATING A CERTIFICATE FROM THE KEY BASIC (SB), while the card (CU3 ) Calculates CERTIFICATE FROM THEIR KEY (SD). THESE CERTIFICATES MUST BE IDENTICAL IN ACCORDANCE WITH THE PROPERTIES OF TRANSFORMATION (T). The invention is especially true secret keys RECORDED IN MEMORY CARDS.