Table of Contents
A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete Communications protocol | protocol that performs a information security | security-related function and applies cryptographic methods, often as sequences of Cryptographic primitive | cryptographic primitives. A protocol describes how the algorithms should be used. A sufficiently detailed protocol includes details about data structures and representations, at which point it can be used to implement multiple, interoperable versions of a program.
Cryptographic protocols are widely used for secure application-level data transport. A cryptographic protocol usually incorporates at least some of these aspects:
- Key agreement or establishment
- Entity authentication
- Symmetric encryption and message authentication key (cryptography) | cryptographic_protocol material construction
- Secured application-level data transport
- Non-repudiation methods
- Secret sharing methods
For example, Transport Layer Security (TLS) is a cryptographic protocol that is used to secure web (HTTPS) connections. It has an entity authentication mechanism, based on the X.509 system; a key setup phase, where a symmetric encryption key is formed by employing public-key cryptography; and an application-level data transport function. These three aspects have important interconnections. Standard TLS does not have non-repudiation support.
There are other types of cryptographic protocols as well, and even the term itself has various readings; Cryptographic application protocols often use one or more underlying key agreement | key agreement methods, which are also sometimes themselves referred to as “cryptographic protocols”. For instance, TLS employs what is known as the Diffie–Hellman key exchange, which although it is only a part of TLS per se, Diffie–Hellman may be seen as a complete cryptographic protocol in itself for other applications.
Examples
- Secure Shell (SSH)
See also
External links
Cryptography: History of cryptography ]] | [[Cryptanalysis ]] | [[Outline of cryptography ]] | [[Symmetric-key algorithm ]] | [[Block cipher ]] | [[Stream cipher ]] | [[Public-key cryptography ]] | [[Cryptographic hash function ]] | [[Message authentication code ]] | [[Cryptographically secure pseudorandom number generator | Random numbers ]] | [[Steganography (Cryptography navbar)