Embodiments provide a computer implemented method of enforcing password uniqueness for different user accounts of a particular user. The method includes: receiving a first new password from a first user account of the particular user, wherein the first user account is associated with a first system/object referenced by a first Password Relationship Object (PRO); evaluating a uniqueness policy to determine whether password uniqueness is required by one or more other PROs, wherein each system/object referenced by the one or more other PROs has a different user account of the particular user; if the password uniqueness is required by the one or more other PROs, evaluating a matching policy to determine whether the first new password matches any password of each different user account associated with one or more systems/objects referenced by the one or more other PROs; if there is a match, enforcing an enforcement policy.