In
cryptography
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), ...
, WAKE is a
stream cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream ( keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystrea ...
designed by
David Wheeler in 1993.
WAKE stands for Word Auto Key Encryption. The cipher works in ''cipher feedback''
mode
Mode ( meaning "manner, tune, measure, due measure, rhythm, melody") may refer to:
Arts and entertainment
* MO''D''E (magazine), a defunct U.S. women's fashion magazine
* ''Mode'' magazine, a fictional fashion magazine which is the setting fo ...
, generating
keystream
In cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a plaintext message to produce an encrypted message (the ciphertext).
The "characters" in the keystream can be bit
The bit is the most basic ...
blocks from previous
ciphertext
In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext ...
blocks. WAKE uses an
S-box
In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Clau ...
with 256 entries of 32-
bit
The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...
words.
The cipher is fast, but vulnerable to
chosen plaintext
Chosen or The Chosen may refer to:
Books
*The Chosen (Potok novel), ''The Chosen'' (Potok novel), a 1967 novel by Chaim Potok
* ''The Chosen'', a 1997 novel by L. J. Smith (author), L. J. Smith
*The Chosen (Pinto novel), ''The Chosen'' (Pinto nov ...
and
chosen ciphertext attack
A chosen-ciphertext attack (CCA) is an attack model for cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden a ...
s.
[Bruce Schneier, ''Applied Cryptography'', Second Edition, page 402.]
Characteristics and vulnerability
WAKE is noted for its speed, making it suitable for applications requiring fast
encryption
In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...
. However, it has been found to be vulnerable to both chosen plaintext and chosen
ciphertext
In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext ...
attacks. These vulnerabilities arise from the cipher's reliance on previous ciphertext blocks for
keystream
In cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a plaintext message to produce an encrypted message (the ciphertext).
The "characters" in the keystream can be bit
The bit is the most basic ...
generation, which can be exploited in certain attack scenarios.
Research has indicated that WAKE's design allows for effective chosen plaintext attacks, where an attacker can choose arbitrary plaintexts to be encrypted and analyze the resulting ciphertexts to gain insights into the key or the encryption process. Similarly, chosen ciphertext attacks can also be executed, where an attacker can manipulate ciphertexts and observe the corresponding plaintext outputs.
Recent developments
While WAKE has been overshadowed by more modern stream ciphers, its study remains relevant in cryptographic research. Ongoing analyses focus on its security properties and potential improvements to mitigate identified vulnerabilities. For instance, some studies have proposed modifications to the
S-box
In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Clau ...
structure or alternative feedback mechanisms to enhance resistance against chosen plaintext and ciphertext attacks.
See also
*
TEA
Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of '' Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of south-western China and nor ...
,
XTEA
In cryptography, XTEA (eXtended TEA) is a block cipher designed to correct weaknesses in TEA. The cipher's designers were David Wheeler and Roger Needham of the Cambridge Computer Laboratory, and the algorithm was presented in an unpublished ...
References
External links
A Bulk Data Encryption Algorithm
Stream ciphers
{{crypto-stub