Example: "The PDF included a digital signature that verified the document's creator."
A digital signature is a block of data that can be attached to documents such as PDFs, word processing files, and e-mail messages. It contains a unique code that verifies a person's identity. Many programs allow users to "digitally sign" documents, which appends a digital signature to the file. By using digital signatures, users can certify documents they have created or approve documents received from others.