Bob outsmarts Alice's one way function

Re:Bob outsmarts Alice's one way function by marcin_kw on Friday April 12, 2013 @08:22AM (#5538001)

The author did not realize that the "repetitive dictionary lookup" function is not a 1-to-1 mapping. There could be, for example, multiple words whose definition starts with "a type". All these words map to the same ciphertext, eventually.

The "repetitive dictionary lookup" function is very useful for validating Alice's claims of solving parts of the puzzle, but imperfect for deriving the solution from a ciphertext.

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Re:Bob outsmarts Alice's one way function by jgrahamc on Friday April 12, 2013 @08:23AM (#5538010)

I didn't? Or perhaps you didn't read my blog post where at the end I say...

"PS In reality, Alice's one way function is not 'bijective'. That means that some starting words will end up at the same word. For example, when FOLIO, PIECE and WORLD are passed through Alice's one way function they all end up at THINGS. In a follow up post I'll take about this and its implications."

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Re:Bob outsmarts Alice's one way function by peteretep on Friday April 12, 2013 @08:51AM (#5538123)

That property is that it's not injective. It is also ("implies") not bijective, but that's a different thing.

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Re:Bob outsmarts Alice's one way function by jgrahamc on Friday April 12, 2013 @09:21AM (#5538269)

True. Given the desire not to talk about mathematics in these blog posts I am opting to excise that rather than fix.

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