What is a Digital Signature?

A large amount of communication takes places these days electronically. People send emails, faxes, and files with the help of computers. With each and every file that is sent electronically, even emails, the possibility for a security breach exists.

Hackers live for challenges, but they make a living from non-challenges. In order to protect data that you transfer electronically, you might want to invest in a digital signature. This is a powerful, technologically advanced way to make sure that your communique reaches only the intended recipient. A digital signature is an electronic signature that can be attached to documents to prove that the original content is still the content of record. In other words, a document containing a digital signature has been certified by its sender as accurate to his or her intentions and has not been altered by an unintended third party.

One of the main components of a digital signature is its timestamp. This tells both the sender and the recipient the exact time at which the file was sent. The sender can match the timestamp to his email or other method of file transfer in order to prove that no one intercepted the file and altered its data in transit, or worse, stole its data for good so that the transfer never took place.

A digital signature is usually the product of a dedicated software application, although it can be included as part of another application. The random number generator function of a computer generates a series of 0s and 1s that make up a letters-and-numbers sequence to protect your data by allowing your intended recipient to verify that the file has been encrypted to your specifications.

Technically, the digital signature process smashes the digital data and all its aspects into a handful of lines of code. This process is called hashing, and the resulting set of coding is called a message digest. The digital signature software then encrypts the message digest. On the other end, a decryption program is required to turn the message digest back into an "unhashed" document.

Something else is going on here as well. The person who creates the digital signature uses a private data "key" to do the hashing. His or her other "key," a public one, is known to the intended recipient. When the sender transmits data using the digital signature, the recipient enters the sender's public key and is able to decrypt the document. Only if the sender's private key, which the recipient doesn't view, is intact will the file appear unblemished, as it was intended.

You don't need to be a code expert to use a digital signature. You just need to have the necessary software on both sides of the digital signature equation. Only then can you be certain that your transferred documents are secure from start to finish.