User:Jr7409/sandbox

An unknown shared secret is a challenge-response logon credential for computing devices that, unlike a known shared secret such as a pre-selected or pre-assigned password, is unknown to the user prior to the time of logon. In the context of a cognitive-based authentication or authorization process, in which the user is prompted with a series of psychometric questions or mental exercises designed to measure the user's cognitive function at the time of logon, the user's responses may form an "unknown" shared secret between the user and the computer. While known shared secrets are typically used to verify a user's identity and/or clearance level, unknown shared secrets provide an additional layer of security by allowing a computer system to determine whether the user demonstrates the required level of cognitive function or mental alertness to gain access to the system. This is particularly useful in environments where computer-based job functions require a high degree of skill, dexterity, alertness, focus, and/or concentration and in situations where users of personal computers suffer from some degree of impairment to their memory or other mental functions due to age, illness, trauma, and/or degenerative conditions.