!!! Overview [{$pagename}] is an [encryption Scheme] that is [Information-theoretic Secure] requires the use of a [random] one-time [Pre-Shared Key] (this is the one-time pad) the same size as, or longer than, the [message] being sent. [{$pagename}] is [Information-theoretic Secure]. However, practical implementation problems have prevented [{$pagename}] from being widely used. [{$pagename}] a [plaintext] is paired with a random one-time [Pre-Shared Key]. Then, each [bit] or character of the [plaintext] is encrypted by combining it with the corresponding [bit] or character from the [{$pagename}]. (Typically using modular addition) Assuming: * the [{$pagename}] is truly [random] * the [{$pagename}] at least as long as the [plaintext] * the [{$pagename}] is __never reused__ in whole or in part * the [{$pagename}]is kept __completely secret__ then [Decryption] of the resulting [ciphertext] will be impossible. Suppose [Alice] wishes to send the [message] "HELLO" to [Bob] without [Eve] decoding the message. Assume two __pads of paper__ containing identical [random] sequences of letters were somehow previously produced and securely issued to [Alice And Bob] and NOT [Eve]. [Alice] chooses the appropriate unused page from the pad. The way to do this is normally arranged for in advance, as for instance 'use the 12th sheet on 1 May', or 'use the next available sheet for the next [message]'. The material on the selected sheet is the [random] one-time [Pre-Shared Key] (or [{$pagename}]) for __this [message]__. Each letter from the [{$pagename}] will be combined in a predetermined way with one letter of the [message]. !! More Information There might be more information for this subject on one of the following: [{ReferringPagesPlugin before='*' after='\n' }] ---- * [#1] - [One-time_pad|Wikipedia:One-time_pad|target='_blank'] - based on information obtained 2017-06-28-