4.5.2 Signature Format

The ECDSA signature that is generated and output by the Sign command or input to the Verify command is always 64 bytes in length. The signature is divided into R and S components. Both components are 32 bytes in length and R always appears before S on the bus. Each portion of the signature appears MSB first on the bus, meaning the MSB of the signature is in the lowest memory location.

Example R/S Signature

Any command that returns a signature (Sign) or accepts a signature as a parameter (Verify) will format the signature as the R and S big-endian unsigned integers concatenated together for a total of 64 bytes.

For example:
    R: 7337887F8C39DF79FD8BF88DDFBFB9DB15D7B1AD68196AE3FB0CE5BFA2842DF3
    S: 72868A43A42831E950E1DA9F73B29F5C0ED8A96B2889E3CBBE8E61EA6C67F673