Two-Channel Authentication Challenge Table Mitigates MITM Attacks
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Solution Overview
Problem
Existing user authentication methods are vulnerable to 'Man In The Middle' (MITM) attacks due to insecure communication channels, which allow attackers to intercept and data mine challenge grids and responses.
Innovation Solution
A method utilizing two separate communication channels for user authentication, where a server generates a challenge table and transmits it to a second user device, which displays it to the user, who then selects characters and submits them through a first channel, with the server verifying the authenticity based on reference locations within the table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single communication channel is used to transmit challenge grids and responses, then the authentication process is simple, but the system becomes vulnerable to MITM attacks
Solution Approach 1:
The authentication communication is segmented into two separate channels: a first communication channel for transmitting the challenge grid from server to user device, and a second communication channel for transmitting the challenge response from user device to server. This segmentation ensures that even if one channel is compromised, the authentication remains secure because the attacker cannot intercept both the challenge and response simultaneously.
Solution Approach 2:
The server acts as an intermediary that generates and distributes challenge grids through the first channel while collecting responses through the second channel. This intermediary role allows the server to control and verify the authentication process, preventing direct interception between user devices and eliminating MITM attack vectors.
2Ease of manufacture
If challenge grids are transmitted through unsecured channels, then the authentication system is easier to implement, but attackers can intercept and data mine authentication data
Solution Approach 1:
By dividing the authentication data transmission into two separate communication channels, the system maintains implementation simplicity while preventing data interception. The challenge grid travels through the first channel and the response through the second channel, so attackers cannot capture both pieces of information needed for successful data mining.
Solution Approach 2:
The system changes the parameter of communication channel structure from a single channel to two separate channels. This parameter change fundamentally alters the security landscape by making simultaneous interception of challenge and response impossible, thereby eliminating the data mining vulnerability while keeping the authentication logic relatively simple.
Data Source
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AI summary
The invention relates to a method (20) for authenticating a user. A server (14) accesses a user identifier associated with a second user device (16) identifier. The server accesses, for the user, a predetermined reference location(s) within a reference table. The method comprises: Sending from a first user device (12) to the server, through a first communication channel, a message (24) including the user identifier and a request to get a challenge table. Generating (26), by the server, a first challenge table including a valid first set of characters. Sending, thanks to the second user device identifier, from the server to the second user device, through a second communication channel, a message (210) including the first challenge table and a first request to display the first challenge table. Displaying (212), by or through the second user device, the first challenge table. Selecting (216), by a user, through a first user device man machine interface, a a selected character(s). Sending, from the first user device to the server, through the first communication channel, a message (220) including the selected character(s), as submitted user authentication data. Determining (224), by the server, based upon the predetermined reference location(s) within the first challenge table a corresponding reference character(s), as reference user authentication data. Verifying (226), by the server, for the user, whether the submitted user authentication data does or does not match the reference user authentication data. And, only if yes, succeeding, by the server, in authenticating the user. The invention also relates to corresponding user devices (12) and (16), server (14) and system (10).