HP Open Source Security for OpenVMS Volume 2: HP SSL for OpenVMS > Chapter 2 Overview of SSL## Digital Signatures
Encryption and decryption address the problem of eavesdropping. However, tampering and impersonation are still possible. Public key cryptography addresses the problem of tampering
using a mathematical function called a For all practical purposes, the content of the hashed data cannot be deduced from the hash, which is why it is called "one-way." This principle is the crucial part of digitally signing any
data. Instead of encrypting the data itself, the signing software
creates a one-way hash of the data, then uses your private key to
encrypt the hash. The encrypted hash, along with other information,
such as the hashing algorithm, is known as a |