The ATECC608 is the latest crypto-auth chip from Microchip, and it uses I2C to send/receive commands. Once you ‘lock’ the chip with your details, you can use it for ECDH and AES-128 encrypt/decrypt/signing. There’s also hardware support for random number generation, and SHA-256/HMAC hash functions to greatly speed up a slower micro’s cryptography commands.
- Cryptographic co-processor with secure hardware-based key storage
- Protected storage for up to 16 Keys, certificates or dataç
- ECDH: FIPS SP800-56A Elliptic Curve Diffie-Hellman
- NIST standard P256 elliptic curve support
- SHA-256 & HMAC hash including off-chip context save/restore
- AES-128: encrypt/decrypt, galois field multiply for GCM
Please note the I2C address is fixed at 0x60 and according to Microchip, you should use this at higher I2C speeds like 400KHz if other devices are on the I2C bus, to avoid some I2C bus contention (much like the datasheet, this is not documented anywhere yet)