Decrypt given data previously encoded with des-cfb cipher algo. DES in CFB (Cipher Feedback) mode, a mode that allows for encryption of smaller blocks of data. CFB mode was introduced to make DES more versatile in handling variable-length data. While CFB provides better security than ECB, DES itself is still considered insecure due to its 56-bit key length. Our decryption process assumes the IV string is prepended in the encoded string during the encryption process. You can not decrypt and get the correct results if the IV or passphrase mismatch occurs between encryption and decryption process.