Discover Cryptography News
OpenSSH key management, Part 2
ssh-agent, included with the OpenSSH distribution, is a special program designed to make dealing with RSA and DSA keys both pleasant and secure (see Part 1 of this series for an introduction to RSA and DSA authentication.) ssh-agent, unlike ssh, is a long-running daemon designed for the sole purpose of caching your decrypted private keys.
ssh includes built-in support that allows it to communicate with ssh-agent, allowing ssh to acquire your decrypted private keys without prompting you for a password for every single new connection. With ssh-agent you simply use ssh-add to add your private keys to ssh-agent's cache. It's a one-time process; after using ssh-add, ssh will grab your private key from ssh-agent, rather than bugging you by prompting for a passphrase.
The link for this article located at IBM developerWorks is no longer available.