How often should an SSH key pair be changed?
I've been using a passphrase-protected 1024-bit RSA key for passwordless SSH via ssh-agent between my own systems for years. More recently I've also started using it for passwordless access to my hosting providers and to source code repositories.
Is using the same key pair for an extended period of time an issue? If so, how long is too long?
Also, is using the same key pair to access multiple resources an issue?