The S/MIME development community benefits from sharing samples of signed or encrypted data. This document facilitates such collaboration by defining a small set of X.509v3 certificates and keys for use when generating such samples.
2.7. Secret Key Origins The secret RSA keys in this document are all deterministically derived using provable prime generation as found in [FIPS186-4] based on known seeds derived via SHA-256 ([SHA]) from simple strings.