# Why do we permute the table-entries of a garbled AND gate?

My problem:

Ana wants to garble an AND gate of a circuit,

• A0 and A1 are the two strings used to represent true and false for the input wire A,
• B0 and B1 are the two strings used to represent true and false for the input wire B,
• C0 and C1 are the two strings used to represent true and false for the output wire.

Explain briefly how Ana computes the garbled table of this gate and why she must permute the table entries.

My attempt to solving this problem:

• Hint: What happens if you don't permute and the evaluator detects that the fourth row has the output key of the gate?
– SEJPM
Feb 9 at 13:50
• @SEJPM , perhaps we permute because we want to eliminate the pattern? what do you mean output-key of the gate?:) Feb 9 at 13:54
• This could help: crypto.stackexchange.com/a/48091/29574
– Lery
Feb 9 at 15:41