mcrypt_decrypt Decrypts crypttext with given parameters &warn.deprecated.function-7-1-0.removed-7-2-0; &reftitle.description; stringfalsemcrypt_decrypt stringcipher stringkey stringdata stringmode stringiv Decrypts the data and returns the unencrypted data. &reftitle.parameters; cipher &mcrypt.parameter.cipher; key The key with which the data was encrypted. If the provided key size is not supported by the cipher, the function will emit a warning and return &false; data The data that will be decrypted with the given cipher and mode. If the size of the data is not n * blocksize, the data will be padded with '\0'. mode &mcrypt.parameter.mode; iv &mcrypt.parameter.iv.strict; &reftitle.returnvalues; Returns the decrypted data as a string &return.falseforfailure;. &reftitle.seealso; mcrypt_encrypt