There may be times when it is desirable to give a secret key, or indirect access to a secret key, to parties other than those directly involved in a secured communication. Unfortunately, most of the time the issue comes up in a context the author finds undesirable, such as providing a (possibly circumscribed) backdoor to "secure" communications to a government/police agency and/or to corporate employers. Cryptography is a technology that cannot be fully considered apart from its political implications.

However, there are other legitimate reasons for key escrow. It may happen that you would like certain people to have the ability to access your secured communications in the event you are no longer able to divulge them yourself (or do not wish to require your effort, given certain circumstances). Two techniques are useful for key escrow goals (and can be used individually or jointly): multiple recipient lists and secret sharing of keys.