```rust
.subcommand(
            SubCommand::with_name("encrypt")
                .about(
                    "Implements encryption of several common classical ciphers",
                )
                .arg(
                    Arg::with_name("type")
                        .short("t")
                        .long("type")
                        .takes_value(true)
                        .help("Select the cipher type"),
                )
                .arg(
                    Arg::with_name("key")
                        .short("k")
                        .long("key")
                        .takes_value(true)
                        .help("Provide the key to use"),
                )
        )
        .subcommand(
            SubCommand::with_name("decrypt")
                .about(
                    "Implements decryption of several common classical ciphers",
                )
                .arg(
                    Arg::with_name("type")
                        .short("t")
                        .long("type")
                        .takes_value(true)
                        .help("Select the cipher type"),
                )
                .arg(
                    Arg::with_name("key")
                        .short("k")
                        .long("key")
                        .takes_value(true)
                        .help("Provide the key to use"),
                )
        );
```