# tcl::transform::otp(3tcl) 1.1 virtchannel_transform "Reflected/virtual channel support"

## Name

tcl::transform::otp - Encryption via one-time pad

## Synopsis

- package require Tcl 8.6 9
- package require tcl::transform::core ?1.1?
- package require tcl::transform::otp ?1.1?

- ::tcl::transform::otp chan keychanw keychanr

## Description

The tcl::transform::otp package provides a command creating a channel transformation which uses externally provided one-time pads to perform encryption (on writing) and decryption (on reading).

A related transformations in this module is tcl::transform::rot.

The internal TclOO class implementing the transform handler is a sub-class of the tcl::transform::core framework.

## API

::tcl::transform::otp chan keychanw keychanr

  This command creates a one-time pad based encryption transformation on top of the channel chan and returns its handle.

  The two channels keychanw and keychanr contain the one-time pads for the write and read directions, respectively. Their contents are reads and xored with the bytes written to and read from the channel.

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category virtchannel of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.

## Keywords

channel transformation, cipher, decryption, encryption, one time pad, otp, reflected channel, tip 230, transformation, virtual channel, xor

## Category

Channels

## Copyright

Copyright © 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>