Abstract: Authenticating access to a system through the following operations: (i) determining at least one digital twin corresponding to a user; (ii) setting, by the user, modifications to at least one digital twin; (iii) generating, by the digital twin, a value based on the modifications; (iv) authenticating the user based on the generated value matching a stored value; and (v) based on the authentication, granting access to the system. A digital twin of a complex entity can have innumerable states based on the input values. In some embodiments, a new password can make an effect on a selected digital twin with one input or a sequence of inputs. The resulting state is transformed using a hashing algorithm to generate the final password, which is known only to the service provider, can act as a password.