Cryptcat is netcat with encryption capabilities.


[l]isten on a specified [p]ort and print any data received

$ cryptcat -k [password] -l -p [port]

Connect to a certain port
$ cryptcat -k [password] [ip_address] [port]

Set a timeout [w]
$ cryptcat -k [password] -w [timeout_in_seconds] [ip_address] [port]

Scan [z] the open ports of a specified host
$ cryptcat -v -z [ip_address] [port]

Act as proxy and forward data from a local TCP port to the given remote host
$ cryptcat -k [password] -l -p [local_port] | cryptcat -k [password] [hostname] [remote_port]


cryptcat -k secret [-options] hostname port[s] [ports]
cryptcat -k secret -l -p port [-options] [hostname] [port]


This manual page documents briefly the cryptcat command. This manual page was written for the Debian GNU/Linux distribution because the original program does not have a manual page. It only documents the features specific to cryptcat and not the features that are described at length in the manpage for nc(1).
If you do not know nc then the chances are you won't have much use for this manpage.

cryptcat can act as a tcp or udp client or server - connecting to or listening on a socket, while otherwise working as the standard Unix command cat(1).

cryptcat takes a password as a salt to encrypt the data being sent over the connection. Without a specified password cryptcat will default to the hardcoded password ``metallica''. Needless to say, failure to specify a different password makes the connection as good as unencrypted.


This programs does not follow the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of the options specific to cryptcat is included below.


Show summary of options.

-k secret password

Change the shared secret password to be used to establish a connection.


This version of cryptcat does not support the -e command command line option available in some versions of nc.


nc(1), cat(1). /usr/share/doc/cryptcat/README.gz /usr/share/doc/cryptcat/README.cryptcat /usr/share/doc/cryptcat/README.Debian


The original netcat was written by

cryptcat is the work of farm9 <> with the help of Dan F, Jeff Nathan, Matt W, Frank Knobbe, Dragos, Bill Weiss, Jimmy.

This manual page was written by Lars Bahner <> for Debian.

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