Why would I want to use it?  
At the moment there is no true method of effectively identifying a person who sends an email message, a digital signature effectively acts like a passport confirming whom you say you are thus making the whole email transaction a little more credible; giving assurance and confidence to your recipient.  It wont be long before the email signature is as the same power by law as the written signature, and so the signature will give your business the power to extend your e-business, signing contracts and other documents via email, saving your company time and money.

 How does it work?

Depending on whom you obtain you certificate from will determine how the signature works.  However most signatures or certificates sit on your computers hard-drive as a small piece of software, and works parallel to your e-mail software.  Most popular email packages will have an option allowing you to attach your digital signature to newly composed messages. Once a signature has been received (email is normally obviously flagged), looking in their email security option the recipient can then access the certificate details and have the sender's identity checked via the company who issued the certificate. This sounds complicated, but if you intend to transmit sensitive documents or agree contractual arrangements, then this can provide a lot of well-needed security.  

How do I obtain a Digital Signature?

Before you can send a digital signature, you must first sign up to a regularity body that specialise in authorising digital signatures. These organisations are known as "Certification Authorities" (CA) and more recently "Trust Service Providers" (TSP).  There aren't a great deal of these organisations at present, however, as demand increases, the number of TSP's will increase. 

 At present the following offer a digital signature and encryption certificates

• Chambersign

• TrustWise

• Identrus

• Verisign

• inter-clear