Red Pike is a classified

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

government encryption algorithm, proposed for use by the

National Health Service The National Health Service (NHS) is the umbrella term for the publicly funded healthcare systems of the United Kingdom (UK). Since 1948, they have been funded out of general taxation. There are three systems which are referred to using the " ...

GCHQ Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the Unit ...

, but designed for a "broad range of applications in the

British government ga, Rialtas a Shoilse gd, Riaghaltas a Mhòrachd , image = HM Government logo.svg , image_size = 220px , image2 = Royal Coat of Arms of the United Kingdom (HM Government).svg , image_size2 = 180px , caption = Royal Arms , date_es ...

. Little is publicly known about Red Pike, except that it is a

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

with a 64-bit block size and 64-bit

key length In cryptography, key size, key length, or key space refer to the number of bits in a key used by a cryptographic algorithm (such as a cipher). Key length defines the upper-bound on an algorithm's security (i.e. a logarithmic measure of the fastest ...

. According to the academic study of the cipher cited below and quoted in a paper by Ross Anderson and Markus Kuhn, it "uses the same basic operations as RC5" (add, XOR, and left shift) and "has no look-up tables, virtually no key schedule and requires only five lines of code"; "the influence of each key bit quickly cascades" and "each encryption involves of the order of 100 operations". Red Pike is available to approved British government contractors in software form, for use in confidential (not secret) government communication systems. GCHQ also designed the

Rambutan Rambutan (; taxonomic name: ''Nephelium lappaceum'') is a medium-sized tropical tree in the family Sapindaceae. The name also refers to the edible fruit produced by this tree. The rambutan is native to Southeast Asia. It is closely related to s ...

cryptosystem for the same segment. Given that Red Pike is a British encryption algorithm, its name likely refers to a particular fell in the western English Lake District.

Supposed source code

In February 2014, the supposed source code for Red Pike was posted as follows to the

Cypherpunk A cypherpunk is any individual advocating widespread use of strong cryptography and privacy-enhancing technologies as a route to social and political change. Originally communicating through the Cypherpunks electronic mailing list, informal g ...

mailing list. "Red Pike cipher"
Red Pike cipher, Cypherpunk mailing list, Gmane /* Red Pike cipher source code */ #include typedef uint32_t word; #define CONST 0x9E3779B9 #define ROUNDS 16 #define ROTL(X, R) (((X) << ((R) & 31)) , ((X) >> (32 - ((R) & 31)))) #define ROTR(X, R) (((X) >> ((R) & 31)) , ((X) << (32 - ((R) & 31)))) void encrypt(word * x, const word * k) void decrypt(word * x, const word * k)

References

* C Mitchell, S Murphy, F Piper, P Wild. (1996). Red Pike — an assessment. Codes and Ciphers Ltd 2/10/96.
Paper by Anderson and Kuhn which includes excerpts from (Mitchell et al., 1996)
Another version is

{{Cryptography navbox , block Block ciphers GCHQ

Supposed source code

See also

References