anchor.diff:  	TaggedIMSI = base64:decode(<<Pseudonym/binary, $A>>),
   	<<_:6, N:4, EncryptedIMSI:16/binary, _:6>> = TaggedIMSI,
   	{_, Kpseu} = lists:keyfind(N, 1, Keys),
  -	PaddedIMSI = crypto:block_decrypt(aes_ecb, Kpseu, EncryptedIMSI),
  +	PaddedIMSI = ?BLOCK_DECRYPT(aes_ecb, Kpseu, EncryptedIMSI),
   	binary:part(PaddedIMSI, 0, 8).
   
   -spec encrypt_key(Secret, RequestAuthenticator, Salt, Key) -> Ciphertext
  
positive.code: 		size(CompressedIMSI) == 8, size(Kpseu) == 16 ->
  	Pad = crypto:strong_rand_bytes(8),
  	PaddedIMSI = <<CompressedIMSI/binary, Pad/binary>>,
  	EncryptedIMSI = crypto:block_encrypt(aes_ecb, Kpseu, PaddedIMSI),
  	TaggedIMSI = <<Tag:6, N:4, EncryptedIMSI/binary, 0:6>>,
  	binary:part(base64:encode(TaggedIMSI), 0, 23).
  
  
negative.code: -on_load(init/0).
  
  -include("ocs_eap_codec.hrl").
  
  -ifdef(OTP_RELEASE).
  	-if(?OTP_RELEASE >= 22).
  		-define(BLOCK_ENCRYPT(Cipher, Key, Data), crypto:crypto_one_time(Cipher, Key, Data, true)).
  		-define(BLOCK_DECRYPT(Cipher, Key, Data), crypto:crypto_one_time(Cipher, Key, Data, false)).
  	-else.
  		-define(BLOCK_ENCRYPT(Cipher, Key, Data), crypto:block_encrypt(Cipher, Key, Data)),
  		-define(BLOCK_DECRYPT(Cipher, Key, Data), crypto:block_decrypt(Cipher, Key, Data)).
  	-endif.
  -else.
  		-define(BLOCK_ENCRYPT(Cipher, Key, Data), crypto:block_encrypt(Cipher, Key, Data)),
  		-define(BLOCK_DECRYPT(Cipher, Key, Data), crypto:block_decrypt(Cipher, Key, Data)).
  -endif.
  
  %% 3GPP TS 23.003 19.3.2 Root NAI
  -define(PERM_AKA,  $0).
  