Keychains were initially developed for Apple's e-mail system,
PowerTalk, in the early 1990s. Among its many features, PowerTalk used
plug-ins that allowed mail to be retrieved from a wide variety of mail servers and online services. The keychain concept naturally "fell out" of this code, and was used in PowerTalk to manage all of a user's various login credentials for the various e-mail systems PowerTalk could connect to. The passwords were not easily retrievable due to the encryption, yet the simplicity of the interface allowed the user to select a different password for every system without fear of forgetting them, as a single password would open the file and return them all. At the time, implementations of this concept were not available on other platforms. Keychain was one of the few parts of PowerTalk that was obviously useful "on its own", which suggested it should be promoted to become a part of the basic Mac OS. But due to internal politics, it was kept inside the PowerTalk system and, therefore, available to very few Mac users. It was not until the return of
Steve Jobs in 1997 that Keychain concept was revived from the now-discontinued PowerTalk. By this point in time the concept was no longer so unusual, but it was still rare to see a keychain system that was not associated with a particular piece of application software, typically a
web browser. Keychain was later made a standard part of Mac OS 9, and was included in
Mac OS X in the first commercial versions. ==Storage and access==