This is the function that verifies the characteristics of a document and a transaction. Characteristics of both are inspected and confirmed for content and correct authorization. Data Integrity is achieved with electronic cryptography that assigns a unique identity to data like a fingerprint. Any attempt to change this identity signals the change and flags any tampering.
Authentication
This inspects, then confirms, the proper identity of people involved in a transaction of data or value. In authentication systems, authentication is measured by assessing the mechanisms strength and how many factors are used to confirm the identity. In a PKI system a Digital Signature verifies data at its origination by producing an identity that can be mutually verified by all parties involved in the transaction. A cryptographic hash algorithm produces a Digital Signature.
Non-Repudiation
This eliminates the possibility of a transaction being repudiated, or invalidated by incorporating a Digital Signature that a third party can verify as correct. Similar in concept to registered mail, the recipient of data re-hashes it, verifies the Digital Signature, and compares the two to see that they match.
