anchor.diff:  %%%----------------------------------------------------------------
   %%%
   %%% Create and initialize a new state for encryption or decryption
  -%%% 
  +%%%
   
   -spec crypto_init(Cipher, Key, EncryptFlag) -> State | descriptive_error()
                                                      when Cipher :: cipher_no_iv(),
  
positive.code: %%% Sign
  
  -spec sign(Algorithm, DigestType, Msg, Key)
            -> Signature 
                   when Algorithm :: pk_sign_verify_algs(),
                        DigestType :: rsa_digest_type()
                                    | dss_digest_type()
  
negative.code: 
  -type hmac_hash_algorithm() ::  sha1() | sha2() | sha3() | compatibility_only_hash().
  
  %%%---- hmac/3,4
  
  -spec hmac(Type, Key, Data) ->
                    Mac when Type :: hmac_hash_algorithm(),
                             Key :: iodata(),
                             Data :: iodata(),
  