Access control system with lockout

A method of limiting the use of a resource to authorized users, comprising the steps of

• (1) assigning specific primary and secondary access codes to each authorized user,
• (2) allowing a user to access said resource by correctly entering the specific primary access code assigned to said user without making more than C.sub.1 incorrect entries in a time period T.sub.1,
• (3) if access is not allowed in step (2), allowing said user to access said resource by correctly entering both the specific primary access code and the specific secondary access code assigned to said user without making more than C.sub.2 incorrect entries in a time period T.sub.2, and
• (4) if access is not allowed in step (3), blocking said user from further access for a predetermined time period even if said user correctly enters both said primary and secondary access codes during said predetermined time period.

A method of controlling access to a telecommunications network by users having first and second assigned passwords, including the steps of

• storing said passwords assigned to each user,
• in response to an access request from a particular user, requesting said user to enter said first password assigned to said particular user,
• comparing said first entered password with said first password assigned to that user to determine if there is a match, whereupon said particular user is granted access to said network,
• if there is not a match in said last mentioned comparing step, repeating, up to C.sub.1 times, said last mentioned requesting and comparing step if said particular user thereafter again attempts access during a time interval T.sub.1,
• in response to an access request from said particular user after C.sub.1 unsuccessful access attempts by said particular user in said time interval T.sub.1, requesting said user to enter said first and second passwords assigned to said particular user,
• comparing said first and second entered passwords with said first password and said second password assigned to that user to determine if there is a match, whereupon said particular user is granted access to said network,
• if there is not a match in said last mentioned comparing step, repeating up to C.sub.2 times, said last mentioned requesting and comparing steps if said particular user thereafter again attempts access during a time interval T.sub.2, and
• in response to an access request from said particular user after C.sub.2 unsuccessful access attempts by said particular user in said time interval T.sub.2, blocking said particular user from further access to said network for a time interval T.sub.L.

An apparatus for controlling access to a resource, including

• (1) means for storing first and second access codes for each user authorized to access said resource,
• (2) means operative in response to a request by a user to access said resource, for comparing a code presented by said user to the first stored access code stored for said user,
• (3) means for allowing said user to gain access to said resource if said presented code matches said first stored access code,
• (4) means for incrementing a first count of unsuccessful access attempts if said presented code does not match said first stored access code,
• (5) means for permitting said user to attempt to gain access to said resource by repeating operation of means (2) through (5), if said first count does not exceed a first threshold value,
• (6) means for advising said user to present first and second codes in order to access said resource, if said first count does exceed said first threshold value,
• (7) means for comparing said first and second codes presented by said user to the first and second stored access codes stored for said user,
• (8) means for allowing said user to gain access to said resource if said presented codes match said first and second stored access codes,
• (9) means for incrementing a second count of unsuccessful access attempts, if said presented codes do not match said first and second stored access codes,
• (10) means for repeating operation of means (6) through (10), if said second count does not exceed a second threshold value, and
• (11) means for denying all attempts by said user to access said resource if said second count does exceed said second threshold value, notwithstanding that said first and second codes presented thereafter by said user match said first and second stored access codes.