The DES cipher should no longer be considered secure. Please consider using a more modern alternative. The bdes utility implements all DES modes of operation described in FIPS PUB 81, including alternative cipher feedback mode and both authentica- tion modes. The bdes utility reads from the standard input and writes to the standard output. By default, the input is encrypted using cipher block chaining (CBC) mode. Using the same key for encryption and decryp- tion preserves plain text.