Thursday, July 31, 2014

What is a digital signature?

What is a digital signature?
A digital signature is an electronic, encrypted, stamp of authentication on digital information such as e-mail messages, macros, or electronic documents. A signature confirms that the information originated from the signer and has not been altered.

Signing certificate and certificate authority
Signing certificate   To create a digital signature, you have to have a signing certificate, which proves identity. When you send a digitally-signed macro or document, you also send your certificate and public key. Certificates are issued by a certification authority, and like a driver’s license, can be revoked. A certificate is usually valid for a year, after which, the signer must renew, or get a new, a signing certificate to establish identity.

Note    You can learn more about public and private keys in this MSDN article.

Certificate authority (CA)   A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Microsoft Office has several solutions for obtaining certificates through Office Marketplace, Digital Signing.

Digital signature assurances
Authenticity   The signer is confirmed as the signer.
Integrity   The content has not been changed or tampered with since it was digitally signed.
Non-repudiation   Proves to all parties the origin of the signed content. Repudiation refers to the act of a signer denying any association with the signed content.
Notarization   Signatures in Microsoft Word 2010, Excel 2010, or PowerPoint 2010 files, which are time stamped by a secure time-stamp server, under certain circumstances, have the validity of a notarization.
To make these assurances, the content creator must digitally sign the content by using a signature that satisfies the following criteria:

The digital signature is valid. 
The certificate associated with the digital signature is current (not expired).
The signing person or organization, known as the publisher, is trusted.
Important  Signed documents, which have a valid time stamp, are considered to have valid signatures, regardless of the age, or revocation status, of the signing certificate.

The certificate associated with the digital signature is issued to the signing publisher by a reputable certificate authority (CA). 

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...

Farm House Plots for Sale


11000 Sq.ft. developed / under development farm house plots for Sale at Morgaon (Supa) near Morgaon Ganesh Temple only for Rs.15 Lacs.... Contact; Atul Karnawat on 9823479955 or Saideep Bagrecha on 7757888883 / 9823979955