can digitally sign a document for many of the same reasons you might sign a paper document. A digital signature is used to authenticate (authenticate: The process of verifying that people and products are who and what they claim to be. For example, confirming the source and integrity of a software publisher's code by verifying the digital signature used to sign the code.) digital information — such as documents, e-mail messages, and macros — by using computer cryptography. Digital signatures help to establish the following assurances:
- Authenticity: The digital signature helps to assure that the signer is who he or she claims to be.
- Integrity: The digital signature helps to assure that the content has not been changed or tampered with since it was digitally signed.
- Non-repudiation: The digital signature helps to prove to all parties the origin of the signed content. "Repudiation" refers to the act of a signer's denying any association with the signed content.
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