Patent ID: 8484455

Claim:
A non-transitory computer readable storage medium having stored thereon program code executable by a computer system, the program code comprising: code that causes the computer system to send, to a user computer, a graphical interface comprising a set of alphanumeric symbols and session-based mapping instructions that uniquely between authentication sessions handed by the computer server correlate each alphanumeric symbol of the graphical interface with a corresponding symbol; code that causes the computer system to receive, from the user computer, encrypted authentication data comprising a sequence of symbols different from authentication data for a user, wherein the encrypted authentication data is generated by the user computer in response to: receiving, via the graphical interface, a sequence of alphanumeric symbols from the user corresponding to the authentication data for the user; and generating the sequence of symbols of the encrypted authentication data based on the sequence of alphanumeric symbols of the graphical interface and the mapping instructions; and code that causes the computer system to decrypt the encrypted authentication data to obtain the authentication data for the user.