AT88SC0404CA-SH [Microchip]

High-performance secure memory that provides 4-Kbit of user memory with advanced security and cryptographic features built-in. The user memory is divided into four 128-byte zones, each of which may be either individually set with different security access rights or effectively combined together to provide space for one to four data files. The device features an enhanced command set that allows direct communication with the microcontroller hardware two-wire interface. This enables faster firmware development with reduced code space requirements.