SIGN instruction

Role

This instruction allows to run a Diffie-Hellman key agreement using one of the ECC private keys stored in the ATECC Secure Element.

Access condition

Depending on the configuration-defined access conditions and on the type of host interface (Local / Remote), this instruction may either be freely usable or restricted to authenticated communications.

Command

Field Value
CLA 59 (ATCRYPTO)
INS 48
Data byte 0 Key index (00 to 0D)
Data byte 1..64 Peer's Public Key X and Y coordinates (2 x 32 = 64 bytes)

Response

Field Value
CLA 59 (ATCRYPTO)
STA 00
Data 0..31 Shared Secret (32 bytes)