19 June 2002

Pinto's Point: Electronic signatures coming of age

By Jim Pinto

Digital signatures are now legally acceptable. Do you have one?

Digital signature technology stems from the need to sign computer-based documents such as e-mail messages or documents within e-mail messages. Signing an electronic document directly, in its electronic form, eliminates the need to put the document on paper in order to sign it. A key element of electronic commerce is creating a legal electronic signature.

In June 2000, the U.S. House and Senate passed the Electronic Signatures in Global and National Commerce Act (E-Sign). The President also signed this important bill, which should increase the growth of electronic commerce by removing a significant barrier to online transactions.

An encryption method is the basis behind the electronic signatures with two encryption keys, one private that does the encrypting and the other public, used for decrypting. The public key may be distributed to all who want it. It will only decrypt messages encrypted with the corresponding private key. Those who like mathematics may want to know that Euler's theorem is the basis behind the system.

An encrypted signature has just a few lines of encryption at the end of a message. Those encryption lines are based on the full text of the message. The message itself remains. If the original message changes in any way, then the signature doesn't verify.

Digital authentication systems will become an essential part of doing business via the Internet. Based on a range of encryption techniques, digital signature systems allow people and organizations to electronically certify such features as their identity, their ability to pay, or the authenticity of an electronic document.

• Introduction to digital signatures
• Identity, authentication, and digital certificates

Behind the byline

Jim Pinto is founder of San Diego–based Action Instruments. You can e-mail him at jim@jimpinto.com, or view his writings at www.JimPinto.com.