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Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.9.5

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	}}</ref> Some authors consider the notation used by Steiner, Neuman, & Schiller<ref>		}}</ref> Some authors consider the notation used by Steiner, Neuman, & Schiller<ref>{{cite conference
	{{cite conference		\|last1 = Steiner
	\| last1 = Steiner		\|first1 = J. G.
	\| first1 = J. G.		\|last2 = Neuman
	\| last2 = Neuman		\|first2 = B. C.
	\| first2 = B. C.		\|last3 = Schiller
	\| last3 = Schiller		\|first3 = J. I.
	\| first3 = J. I.		\|date = February 1988
	\|date=February 1988		\|title = Kerberos: An Authentication Service for Open Network Systems
	\| title = Kerberos: An Authentication Service for Open Network Systems		\|conference = Usenix
	\| conference = Usenix		\|book-title = Proceedings of the Winter 1988 Usenix Conference
	\| book-title = Proceedings of the Winter 1988 Usenix Conference		\|publisher = USENIX Association
	\| publisher = USENIX Association		\|location = Berkeley, CA
	\| location = Berkeley, CA		\|pages = 191–201
	\| pages = 191–201		\|url = http://clifford.neuman.name/publications/1988/198802-Usenix-Kerberos/198802-Usenix-Steiner-Neuman-Schiller-Kerberos.pdf
	\| url = http://clifford.neuman.name/publications/1988/198802-Usenix-Kerberos/198802-Usenix-Steiner-Neuman-Schiller-Kerberos.pdf		\|access-date = 2009-06-10
	\| access-date = 2009-06-10		\|archive-date = 2010-08-06
			\|archive-url = https://web.archive.org/web/20100806141601/http://clifford.neuman.name/publications/1988/198802-Usenix-Kerberos/198802-Usenix-Steiner-Neuman-Schiller-Kerberos.pdf
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	}}</ref> as a notable reference.<ref>		}}</ref> as a notable reference.<ref>
	{{cite book		{{cite book

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{{Short description|Notation for communication protocols}}
In [[cryptography]], '''security (engineering) protocol notation''', also known as '''protocol narrations'''<ref>{{cite book|last1=Briais|first1=Sébastien|last2=Nestmann|first2=Uwe|title=Trustworthy Global Computing |chapter=A Formal Semantics for Protocol Narrations |series=Lecture Notes in Computer Science |date=2005|volume=3705|pages=163–181|doi=10.1007/11580850_10|bibcode=2005LNCS.3705..163B|isbn=978-3-540-30007-6|chapter-url=http://sbriais.online.fr/papers/A_Formal_Semantics_For_Protocol_Narrations_TGC05-final.pdf}}</ref> and '''Alice & Bob notation''', is a way of expressing a [[cryptographic protocol|protocol]] of correspondence between entities of a dynamic system, such as a [[computer network]]. In the context of a [[formal model]], it allows reasoning about the properties of such a system.

The standard notation consists of a set of principals (traditionally named [[Alice and Bob|Alice, Bob]], Charlie, and so on) who wish to communicate. They may have access to a server S, shared keys K, timestamps T, and can generate [[cryptographic nonce|nonces]] N for authentication purposes.

A simple example might be the following:

:<math>A\rightarrow B:\{X\}_{K_{A,B}}</math>

This states that '''A'''lice intends a message for '''B'''ob consisting of a [[plaintext]] '''X''' encrypted under shared key '''KA,B'''.

Another example might be the following:

:<math>B\rightarrow A:\{N_B\}_{K_A}</math>

This states that '''B'''ob intends a message for '''A'''lice consisting of a [[cryptographic nonce|'''n'''once]] '''NB''' encrypted using public key of Alice.

A key with two subscripts, '''KA,B''', is a [[symmetric key]] shared by the two corresponding individuals. A key with one subscript, '''KA''', is the public key of the corresponding individual. A private key is represented as the [[Inverse function#Notation|inverse]] of the public key.

The notation specifies only the operation and not its semantics — for instance, private key encryption and signature are represented identically.

We can express more complicated protocols in such a fashion. See [[Kerberos (protocol)|Kerberos]] as an example. Some sources refer to this notation as ''Kerberos Notation''.<ref>
{{ cite journal
| last=Chappell
| first=David
| year=1999
| title=Exploring Kerberos, the Protocol for Distributed Security in Windows 2000
| journal=Microsoft Systems Journal
| url=https://www.microsoft.com/msj/0899/kerberos/kerberos.aspx
| archive-url=https://web.archive.org/web/20170815043157/https://www.microsoft.com/msj/0899/kerberos/kerberos.aspx
| url-status=dead
| archive-date=2017-08-15
}}</ref> Some authors consider the notation used by Steiner, Neuman, & Schiller<ref>
{{cite conference
| last1 = Steiner
| first1 = J. G.
| last2 = Neuman
| first2 = B. C.
| last3 = Schiller
| first3 = J. I.
|date=February 1988
| title = Kerberos: An Authentication Service for Open Network Systems
| conference = Usenix
| book-title = Proceedings of the Winter 1988 Usenix Conference
| publisher = USENIX Association
| location = Berkeley, CA
| pages = 191–201
| url = http://clifford.neuman.name/publications/1988/198802-Usenix-Kerberos/198802-Usenix-Steiner-Neuman-Schiller-Kerberos.pdf
| access-date = 2009-06-10
}}</ref> as a notable reference.<ref>
{{cite book
|author1=Davis, Don |author2=Swick, Ralph | title=Workstation Services and Kerberos Authentication at Project Athena
| date = 1989-03-17
| url = ftp://athena-dist.mit.edu/pub/ATHENA/kerberos/doc/user2user.ps
| format = PS
| access-date = 2009-06-10
| quote = …our notation follows Steiner, Neuman, & Schiller,…
| page = 1
}}</ref>

Several models exist to reason about security protocols in this way, one of which is [[BAN logic]].

Security protocol notation inspired many of the programming languages used in [[choreographic programming]].

== References ==
<references />

[[Category:Cryptography]]

{{crypto-stub}}

Security protocol notation - Revision history

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