What is a digital signature?
A digital signature is an electronic signature affixed to a message or a document. It can be used to authenticate the sender or signer of the message or document, and to verify that the original content has not been altered in any way. A digital signature can be affixed to any kind of message or document, whether it is encrypted or not.
Digital signatures (standard electronic signatures) take the concept of traditional paper-based signing and turn it into an electronic “fingerprint.” This “fingerprint,” or coded message, is unique to both the document and the signer and binds both of them together. The digital signature ensures the authenticity of the signer. Any changes made to the document after it is signed invalidate the signature, thereby protecting against signature forgery and information tampering. Digital signatures help organizations sustain signer authenticity, accountability, data integrity and non-repudiation of electronic documents and forms.
A digital signature is the electronic equivalent of a handwritten signature, verifying the authenticity of electronic documents. In fact, digital signatures provide even more security than their handwritten counterparts. Some banks and package delivery companies use a system for electronically recording handwritten signatures. Some even go so far as to use biometric analysis to record the speed with which you write and even how hard you press down, ensuring the authenticity of the signature. However, this is not what is usually meant by digital signatures–a great relief to those of us with limited budgets and resources. More often than not a digital signature uses a system of public key encryption to verify that a document has not been altered.
