How is a private key used to create a digital signature?
Digital signature technology capitalizes on the fact that every digital document—no matter what kind of file it is—is essentially a long series of ones and zeroes. Since digital documents are just long string of numbers, mathematical functions can be performed on them. The process begins with an unsigned document: • Once a digital document is ready to be signed, the document’s numerical code is processed through a special mathematical operation called a hash function. This creates a new document called a document fingerprint, also referred to as a message digest. • The document fingerprint and private key are used in a second operation called a signature function. This process uses the private key to encrypt the document fingerprint, resulting in a digital signature. The digital signature is like a locked box containing the document fingerprint. The only way to unlock this box is to use the public key of the user who locked it. • The digital signature is embedded within the original do
