Secret information, such as seeds, codes, and keys, can be automatically renegotiated between at least one sender and at least one recipient. Various mechanisms, such as counters, events, or challenges, can be used to trigger automatic renegotiations through various requests or communications. These changes can cause the current secret information to diverge from older copies of the secret information that might have been obtained by unintended third parties. In some embodiments, a secret can be configured to “decay” over time, or have small changes periodically introduced that can be determined to be valid by an authorized party, but can reduce the effectiveness of prior versions of the secret information.