Digital Signatures

One of the key technologies helping to make certificates work is digital signatures. A digital signature is basically a one-way hash of the message, or of whatever is being signed. This hash is then encrypted using the private key of the signer. The recipient of the message creates his or her own one-way hash of the message and then decrypts the signature hash and compares the two hashes. If the hashes match, the signature is valid, and the message hasn't been altered or tampered with since being signed. This process is illustrated in Figure 1.6.

Figure 1.6. The digital signature process.

One-Way Hash

A one-way hash is like ...

Get Developing Secure Applications with Visual Basic now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.