Editing One-time pad (section)

=== Applicability ===

Despite its problems, the one-time-pad retains some practical interest. In some hypothetical espionage situations, the one-time pad might be useful because encryption and decryption can be computed by hand with only pencil and paper. Nearly all other high quality ciphers are entirely impractical without computers. In the modern world, however, computers (such as those embedded in [[mobile phone]]s) are so ubiquitous that possessing a computer suitable for performing conventional encryption (for example, a phone that can run concealed cryptographic software) will usually not attract suspicion.
* The one-time-pad is the optimum cryptosystem with theoretically perfect secrecy.<ref name="Shannon" />
* The one-time-pad is one of the most practical methods of encryption where one or both parties must do all work by hand, without the aid of a computer. This made it important in the pre-computer era, and it could conceivably still be useful in situations where possession of a computer is illegal or incriminating or where trustworthy computers are not available.
* One-time pads are practical in situations where two parties in a secure environment must be able to depart from one another and communicate from two separate secure environments with perfect secrecy.
* The one-time-pad can be used in [[superencryption]].<ref>A "way to combine multiple block algorithms" so that "a cryptanalyst must break both algorithms" in §15.8 of ''Applied Cryptography, Second Edition: Protocols, Algorithms, and Source Code in C'' by Bruce Schneier. Wiley Computer Publishing, John Wiley & Sons, Inc.</ref>
* The algorithm most commonly associated with [[quantum key distribution]] is the one-time pad.<ref name=":1" />
* The one-time pad is mimicked by [[stream cipher]]s.<ref name=":0" />
* [[Numbers station]]s often send messages encrypted with a one-time pad.<ref name="Numbers Stations" />