Authentication Table Guide

The Authentication Table sheet enhances communication security through a challenge-response system for verifying identities. By filling out the sheet with random letters and numbers, you can greatly enhance your identity verification strategies.

The sheet has three tables with two distinct sections:

• Main Letter Grid: This section has columns labeled A through M across the top and rows labeled N through Z along the left side. The squares at the intersection of each row and column are filled with random letters.
• Secondary Number Grids: At the bottom of the sheet, you'll find two smaller squares filled with random numbers:
• Number Grid One: This grid has columns labeled 1 through 5 at the top and rows labeled 6, 7, 8, 9, and 0 on the left.
• Number Grid Two: This grid has rows labeled 1 through 5 on the left and columns labeled 6, 7, 8, 9, and 0 at the top.

These tables serve as your shared secrets for verifying identities.

Here's how to use the Authentication Table:

1. Share Your Table Securely:

Securely share an exact copy of the randomized Authentication Table with your trusted communication group before use.

2. Understand the Challenge-Response Format (Letters):

For the main letter grid:

• Challenger: Issues a challenge using one row letter (N-Z) and one column letter (A-M), e.g., "Authenticate Sierra Echo."
• Responder: Identifies the letter at the intersection and responds with, "I authenticate Sierra Echo with [the letter at the intersection]."
• Verifier: Checks if the letter matches their table.

3. Understand the Challenge-Response Format (Numbers):

You can also use the two smaller number grids for authentication:

• Challenger (Number Grid One): Issues a challenge using a row number (6-0) and a column number (1-5), e.g., "Authenticate Six Three."
• Responder: Identifies the number at the intersection on Number Grid One and responds with, "I authenticate Six Three with [the number at the intersection]."
• Verifier: Checks if the number matches their Number Grid One.
• Challenger (Number Grid Two): Issues a challenge using a row number (1-5) and a column number (6-0), e.g., "Authenticate Two Seven."
• Responder: Identifies the number at the intersection on Number Grid Two and responds with, "I authenticate Two Seven with [the number at the intersection]."
• Verifier: Checks if the number matches their Number Grid Two.

Example Scenario:

Alice and Bob have shared their randomized Authentication Table.

• Letter Authentication:
• Alice: "Bob, authenticate Sierra Echo."
• Bob: "I authenticate Sierra Echo with the letter Papa."
• Alice verifies the letter at Row S, Column E on her table. Important: Both Alice and Bob should now strike out the letter 'P' at that intersection on their tables to prevent its reuse.
• Number Authentication (Grid One):
• Alice: "Bob, authenticate Nine One."
• Bob: "I authenticate Nine One with the number Four."
• Alice verifies the number at Row 9, Column 1 on her Number Grid One.
• Number Authentication (Grid Two):
• Alice: "Bob, authenticate Three Eight."
• Bob: "I authenticate Three Eight with the number Seven."
• Alice verifies the number at Row 3, Column 8 on her Number Grid Two.

Key Things to Remember When Using Your Authentication Table:

• Verify Before Sharing: Always authenticate before sharing sensitive information.
• Use Clear Phrases: Clearly state the row and column (using phonetic alphabet for letters within the authentication phrase and spelling out numbers).
• Treat Your Table Like a Key: Keep your copy private and secure.
• Consider Multiple Authentications: Use multiple challenges (letter and/or number) for higher security.
• Specify the Grid (for Numbers): When using the number squares, ensure both parties know which grid (One or Two) is being referenced.
• Strike Out Used Letters: After each successful letter authentication using the main grid, both the challenger and the responder should immediately strike out the used letter on their respective tables. This ensures that the same letter is not used again, enhancing the security of the system.

By using all sections of the Authentication Table diligently and correctly, and by striking out used letters, you can establish a robust system for verifying identities during communication.