!!! Overview [1]
[{$pagename}] is a mathematical scheme for demonstrating the [Authenticity] of a digital [message] or [data].

%%warning
[Digital Signature Algorithms] and therefore [{$pagename}] are not [Encryption] even though they are [Cryptographic Primitives]
%%

[{$pagename}] is the output ([hash]) of a [Cryptographic Hash Function] when applied to a stream of [data].

A valid [{$pagename}] for a [message] sent from [Alice] gives a [Bob] a high [Level Of Assurance] to [trust] that: 
* [Authentication] - the [message] was created by a known [Alice] AND
* [Non-Repudiation] - that the [Alice] cannot deny having sent the [message] AND
* [integrity] - that the [message] was not altered in since the [{$pagename}] was applied AND
* [Authentication] - the [message] was created by a known [Alice] (Assumes the recipient has a method to know that [Alice] is the owner of the [Public Key])

[{$pagename}] are commonly used for [Public Key Infrastructure], [financial] transactions, and in other cases where it is important to detect [Authenticity] or [integrity].[1]

[{$pagename}]s are based on [Public Key] [cryptography], also known as [Asymmetric Key Cryptography]


!! [{$pagename}]s and Paper Signatures
[{$pagename}]s schemes, invented by [Diffie-Hellman] and formalized by Goldwasser, Micali and Rivest, not only provide the electronic equivalent of signing a paper document with a pen but also are an important building block for many [cryptographic] [protocols] such as [anonymous]
voting schemes, e-cash, and [Anonymous Credential] schemes, to name just a few.

!! [{$pagename}] vs. electronic signature

Unlike [Electronic Signatures], [{$pagename}] employ the use of mathematical [algorithms] to verify the signer’s identity. [Electronic Signatures] on the other hand, are simply used to digitally capture a signer’s intent to sign. It may be an electronic mark, symbol, sound or writing.

The major distinction between forms of signature is that digital signatures use a [Public Key Infrastructure] ([PKI]) to identify both the individual signing a document and the other party requesting the signature while an [Electronic Signature] does not.

Of worthy note is that both [Electronic Signature] and [{$pagename}] are [legally|Legal] binding. [Electronic Signatures] are also the most common. Digital signatures are mostly used in critical financial transactions and transactions that need an extra level of confidentiality and security.

Some signing products use both forms when signing a documents.


!! How [{$pagename}] works
[{$pagename}] requires a [Digital Signature Algorithm] which includes:
* [Signature Generation] 
* [Signature Verification]

!! Why [Hash Function] vs [Encryption]?
The reason for encrypting the [hash] instead of the entire [message] or document is that a [Hash Function] can convert a [Message] into a fixed length value, which is usually much shorter and faster and requires less [CPU] since [hashing] is much faster than signing.

!! [Digital Signature Algorithms]
* [Digital Signature Standard]
* [RSA]
* [Elliptic Curve Digital Signature Algorithm]

!! [Signatures with efficient protocols]
[Signatures with efficient protocols] are a form of [{$pagename}]e invented by Jan Camenisch and Anna Lysyanskaya in 2001. In addition to being secure digital signatures, they need to allow for the efficient implementation of two protocols

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]
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* [#1] - [Digital Signature|Wikipedia:Digital_signature|target='_blank'] - based on information obtained 2013-04-10