Password authentications using triangles and straight lines

In this paper, two password authentication schemes, based on triangle and straight line encoding, respectively, are proposed. In our schemes, a one-way function and a strong cryptographic operation such as DES (data encryption standard) are adopted. Besides, in each scheme, the system only needs to store a secret key pair, and each user can select his own password freely. Instead of storing a password verification table inside the computer system, both methods proposed only have to store a corresponding table of identities, which is used by the computer system for validating the submitted passwords. Owing to these two schemes quickly and efficiently responding to any log-in attempt, they are suitable for real-time applications. Furthermore, in each scheme, the system does not need to reconstruct any term of the existing key table when a new user is inserted into the system. Thus, these two schemes are suitable for practical implementation.