Org.BouncyCastle.Bcpg.OpenPgp.PgpSecretKeyRing
public static PgpSecretKeyRing CopyWithNewPassword(PgpSecretKeyRing ring, char[] oldPassPhrase, char[] newPassPhrase, SymmetricKeyAlgorithmTag newEncAlgorithm, SecureRandom rand)
public static PgpSecretKeyRing ReplacePublicKeys(PgpSecretKeyRing secretRing, PgpPublicKeyRing publicRing)