derivation-code [ noun ]
AI–generated Summary
A special character that encodes the derivation process, added to the identifier.
Definition
To properly extract and use the public key+ embedded in a self-certifying identifier+ we need to know the cryptographic signing scheme used by the key pair+. KERI includes this very compactly in the identifier, by replacing the pad character (a character used to fill a void to able to always end up with a fixed length public key) with a special character that encodes the derivation process. We call this the derivation code.
Example
For example suppose that the 44 character Base-64 with trailing pad character for the public key is as follows: F5pxRJP6THrUtlDdhh07hJEDKrJxkcR9m5u1xs33bhp= If B is the value of the derivation code then the resultant self-contained string is as follows: BF5pxRJP6THrUtlDdhh07hJEDKrJxkcR9m5u1xs33bhp
F5pxRJP6THrUtlDdhh07hJEDKrJxkcR9m5u1xs33bhp=
BF5pxRJP6THrUtlDdhh07hJEDKrJxkcR9m5u1xs33bhp
Relation with KERI
All crypto material appears in KERI in a fully qualified+ representation. This includes a derivation code prepended to the crypto-material.
KERI
Example KERI derivation codes
Beware
Key derivation functions are not related to the pre-pended derivation codes used in KERI.