In this day of hightened security concerns and massive computing power it is more important than ever to utilize every tool we have to prevent unauthorized access to our systems. We've relied on passwords for years and we've learned that users typically don't do a good job with maintaining strong, hack-resistant words and phrases, instead gravitating towards simple words or sports team names that are incredibly easy to guess. Enter Public Key Infrastructure (PKI) cryptography for authenticating your users.

Public key authentication is enabled by default under Fedora 18. Use of keys is addressed with the PubKeyAuthenticationand AuthorizedKeys options.

For information on configuring clients to use ssh keys, see Section 2.2, “Cryptographic Logon”