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#41 octopuppy

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Posted 27 October 2010 - 10:30 PM

Spoiler for Your hypothesis ...


Spoiler for so...

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#42 araver

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Posted 27 October 2010 - 10:34 PM

OK, since the discussion is heating up, I'll refrain from any hints.
-------------------------------------------------------------------------------

After stopping the system, the successful Hacker finds in the Evil Mastermind's abandoned lair an alphabetical list with some of the next passwords. As he tries to unravel the mystery of the algorithm, he shares the list with the community:

ALABAMA - A0A4L2A5
ALASKA - A0K3L1S3
ARIZONA - I0A4R2I5
ARKANSAS - K1A3A3K4
CALIFORNIA - L1R5C0I5
DELAWARE - L0R4E3A4
FLORIDA - O1A3F2O4
GEORGIA - O1A4G2O5
ILLINOIS - L1I4I3L5
KANSAS - N1A2K1N3
KENTUCKY - N0K2E3T2
MASSACHUSETTS - S0S4A3S4
MICHIGAN - C1A3M3C4
MINNESOTA - N0O4I4N4
MISSISSIPPI - S0I4I1S5
MISSOURI - S0R4I3S4
MONTANA - N0A3O2N4
NEWHAMPSHIRE - W0R4E2H4
NEWJERSEY - W1S3N4J3
NEWMEXICO - W1I4N4W5


Some states are still missing, but maybe the critical mass of information has been reached?

Edited by araver, 27 October 2010 - 10:34 PM.

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#43 araver

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Posted 27 October 2010 - 10:42 PM

Spoiler for so...

Spoiler for Now this is interesting

Edited by araver, 27 October 2010 - 10:43 PM.

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#44 octopuppy

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Posted 27 October 2010 - 10:52 PM

Spoiler for Now this is interesting

I agree, and looking at MASSACHUSETTS, MISSISSIPPI and NEWHAMPSHIRE this is evidently not so simple. They seem to follow the rule as I originally stated it. Intriguing...
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#45 dawh

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Posted 27 October 2010 - 11:00 PM

Well, MICHIGAN, FLORIDA, CALIFORNIA and others all violate the rule I noticed about separated consonants, so it seems to have been something of a fluke. :wacko:

Edit: I'm wondering if this algorithm breaks octopuppy's stipulation that the rule be easy to process in your head... :unsure: :P

Edited by dawh, 27 October 2010 - 11:02 PM.

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#46 araver

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Posted 27 October 2010 - 11:14 PM

Spoiler for Now this is interesting


Later edit (decided this part does not need spoilers - it's open and open to discussion).

I still think that such a rule - expressed as an IF(C(x)) THEN A(x) ELSE B(x) rule - contradicts (at least the spirit of) the original Game Rules if the B branch is less than 50% than the number of cases. If A(x) is constant I do not think that you can guess the algorithm B(x) due to a very small number of occurrences which is why I do not feel it is "practically" breakable in this game.

The argument above holds with one exception - If by chance the ABORT command is on the most probable branch, it can still be guessed because guessing does not hurt *that much* in the game.

Spoiler for Which is why

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#47 araver

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Posted 27 October 2010 - 11:17 PM

Edit: I'm wondering if this algorithm breaks octopuppy's stipulation that the rule be easy to process in your head... :unsure: :P


:P
Spoiler for In my defence

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#48 araver

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Posted 27 October 2010 - 11:26 PM

Well, MICHIGAN, FLORIDA, CALIFORNIA and others all violate the rule I noticed about separated consonants, so it seems to have been something of a fluke. :wacko:


Yes, it's not the intended algorithm but I think it would be an interesting valid rule for an algorithm in a different game as ABORT does not have separated consonants and falls on the most frequent branch. It might still raise some objections depending on each player's view on the game rules.
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#49 octopuppy

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Posted 28 October 2010 - 12:11 AM

Yes, it's not the intended algorithm but I think it would be an interesting valid rule for an algorithm in a different game as ABORT does not have separated consonants and falls on the most frequent branch. It might still raise some objections depending on each player's view on the game rules.

Maybe the consistency rule isn't working quite as I intended it. When writing that I was thinking in terms of operations which are used repeatedly (as in the first game). But here each operation applies only once within each clue and the 50% rule pretty much rules out any IF A THEN B ELSE C operation if applied only once per clue (since if B occurs more than half the time, C won't, and vice versa). That's probably too restrictive. What matters is that the hackers get to see enough examples of the rule that they can deduce it, so I wouldn't get hung up on that too much. It probably needs to be worded differently.

As to whether brute force attacks are appropriate, my inspiration for this game is the real-life problem of creating secure passwords as a hash of website names. Such a system needs to be resistant to a little guessing, since a hacker who has obtained some of your passwords may well try a few likely-looking combinations without knowing the entire system. IMO that is in the spirit of the game as it's part of the challenge to build in resistance to that. Plus, it would take enormous restraint not to make guesses knowing the password could only be one of four! It is, after all, a race between the hackers. The brute force applicable is limited by the fact that they only get one guess for every 3 states you destroy.

Unrelated: the 40 seconds restriction (and also the fact that you don't see the password letters so you need to recompute previous variables/letters) does impose serious constraints on the obscurity of a rule. Again, IMHO, it should be even simpler to decide these booleans if they are used more than once.

There is no need to recalculate anything you can keep track of in your head. For most people that would not be very much, but still, reusing a couple of booleans is fine, and cuts down on thinking time.
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#50 araver

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Posted 28 October 2010 - 01:13 AM

Maybe the consistency rule isn't working quite as I intended it. When writing that I was thinking in terms of operations which are used repeatedly (as in the first game). But here each operation applies only once within each clue and the 50% rule pretty much rules out any IF A THEN B ELSE C operation if applied only once per clue (since if B occurs more than half the time, C won't, and vice versa). That's probably too restrictive. What matters is that the hackers get to see enough examples of the rule that they can deduce it, so I wouldn't get hung up on that too much. It probably needs to be worded differently.

I agree.

As to whether brute force attacks are appropriate, my inspiration for this game is the real-life problem of creating secure passwords as a hash of website names. Such a system needs to be resistant to a little guessing, since a hacker who has obtained some of your passwords may well try a few likely-looking combinations without knowing the entire system. IMO that is in the spirit of the game as it's part of the challenge to build in resistance to that. Plus, it would take enormous restraint not to make guesses knowing the password could only be one of four! It is, after all, a race between the hackers. The brute force applicable is limited by the fact that they only get one guess for every 3 states you destroy.

There is no need to recalculate anything you can keep track of in your head. For most people that would not be very much, but still, reusing a couple of booleans is fine, and cuts down on thinking time.


I know the real-life problem is often solved with brute-attacks, no argument for me there. This however is a small scale model - 51/3=17 - at most 16 guessing rounds.

I still would have liked to "patch" it up a little. I would have been much happier designing something that does not suggest a brute-force attack is feasible e.g. the algorithm in the first game. As I said, I was too anxious to start the game :D
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