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07-08 Permute Outputs

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    That means, in our garble table we'll have our outputs encrypted with different keys
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    corresponding to inputs that corresponds to that output value.
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    Of course, we can't send that whole table. That would reveal the values of a0 and b0.
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    We need to remove this part of the table.
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    Then we need to randomly permute the order of these entries.
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    The other thing will do is add some padding.
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    That means after the garbling we'll have a table that's looks like this.
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    Because each of these values is encrypted with a different key,
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    the evaluator can't tell which one is which.
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    The evaluator still needs to be able to decrypt these to produce the right output.
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    The question is how does the evaluator know what the output of that truth table is?
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    The evaluator could try decrypting all the entries and pick the one that seems correct.
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    The evaluator could try decrypting all the entries using the input value keys known to the evaluator,
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    and use the one that decrypts to something of the form pad concatenated with x,
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    and then use this value as the output, or it is not possible
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    based on what the evaluator knows.
Title:
07-08 Permute Outputs
Team:
Udacity
Project:
CS387 - Applied Cryptography
Duration:
01:01
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