You are prompted for a passphrase the first time you use the Key Agent. Use this phrase whenever you need to unlock the agent.
A passphrase is similar to a password, except it can be a phrase with a series of words, punctuation, numbers, white space, or any string of characters you want. Passphrases improve security by limiting access to secure objects, such as private keys and the Key Agent.
Good passphrases are 10-30 characters long, are not simple sentences or otherwise easily guessable, and contain a mix of upper and lower case letters, numbers, and non-alphanumeric characters. The passphrase is case-sensitive.