In modern

cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adve ...

, null encryption (or selecting null cipher or NONE cipher) is choosing not to use encryption in a system where various encryption options are offered. When this option is used, the text is the same before and after encryption, which can be practical for testing/debugging, or

authentication Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicat ...

-only communication. In mathematics such a function is known as the

identity function Graph of the identity function on the real numbers In mathematics, an identity function, also called an identity relation, identity map or identity transformation, is a function that always returns the value that was used as its argument, unc ...

. Examples of this are the "eNULL" and "aNULL" cipher suite in

OpenSSL OpenSSL is a software library for applications that provide secure communications over computer networks against eavesdropping or need to identify the party at the other end. It is widely used by Internet servers, including the majority of HT ...

, and the "NULL Encryption Algorithm" in

IPSec In computing, Internet Protocol Security (IPsec) is a secure network protocol suite that authenticates and encrypts packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. It is used in ...

.RFC 2410 - The NULL Encryption Algorithm and Its Use With IPsec

References

Ciphers {{Crypto-stub

See also

References