Digital Signature

Digital Signature - A core function of a public key infrastructure (PKI). A digital signature can proveentity because it is created with the private key portion (which only the key holder should access) of a public/private key pair. Anyone with the sender's widely published public key can decrypt the signature and, by doing so, receive the assurance that the data must have come from the sender (nonrepudiation of the sender) and that the data has not changed (integrity). The data that is encrypted with the private key is not the entire message, but a short, fixed-length block of data that is computed from the message using a so-called "hash" function. (Gartner definition) 

Source: The Data Governance Institute, 30 November 2009 08:52:57, http://www.datagovernance.com/glossary-governance/

---

These advertisers support this free service

---

Digital signature - Unlike the handwritten signature, which does not change very much over time, the digital signature is unique to every document that is signed. The digital signature makes use of the fact that, using an algorithm, it is possible to calculate a unique numeric value for any given document. This value can be encrypted using an asymmetric algorithm presenting a private key, and adding a public key certificate.   This collection of items is the 'digital signature'.   Quite a bit more complicated that a handwritten one.   However, unlike the handwritten signature, anyone can, using the public key and its associated certificate, decrypt the unique value.   Also, they can calculate that value for themselves by using the same algorithm. If the two values are equal they can be certain of two things.   That the owner/controller of the private key 'signed' the document and that the document has not been altered or forged.   In its way, then, the digital signature is much more powerful than the handwritten signature because it can prevent any change to a document after it has been digitally signed.

[Category=Geospatial ]

Source: Arctic Soft, 06 August 2011 08:27:52, http://www.articsoft.com/it_security.htm

---

digital signature - A digital signature uses encryption technology to do two things. It proves that the message hasn't been changed in transit, called message integrity, and it also links ownership to the information, called non-repudiation.

In order to prove that the message wasn't changed the message is cryptographically transformed to a set of values, called a hash or a digest. The hash or digest is also sometimes referred to as a fingerprint because statistically, the chance of this hash or digest being the same value for any other message is almost impossible. The hash or digest is sent along with the message and the same transformation is run at the other end. Any attempts to alter the information in transit will result in a message that no longer matches its digital signature.

In order to link ownership, before the message is sent, a second operation is performed. The private key of the sender is used to encrypt the hash or digest. The receiver uses the sender's public key to decrypt the digest. This proves that the message could only come from the person who holds the private key.

[Category=Geospatial ]

Source: RSA, 12 August 2011 09:19:32, http://www.rsa.com/glossary/