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araver

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Posts posted by araver

  1. Nope.[...]

    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.

    when I was making the algorithm, even if I implemented a rule which might make an unbalanced tree of decisions, I checked that at least the ABORT command is on one of the most frequent branches.

    I did not realize that doing this can lead to brute force attacks early in the game. Even if the rule is obscure - few boolean choices can always be attacked by brute force. IMHO, brute-force attacks are also not in the spirit of the game, but there is no natural protection against those :)

    Also, I found no way to patch the algorithm up in time 'cause I was anxious to start the game :D

    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.

  2. Is your rule that you count 7 characters along, and if you hit the end you just alternate between the last 2 characters?

    Nope.

    But that is indeed the simplest extension of Cherry Lane's observation to a full rule.

    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.

  3. 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?

  4. Looks like Cherry Lane was right after all!

    Yes,

    between 7 to 13 letters. If different states were played (for example no states with 11 or more characters), her rule would have been flawless ... except for commands with 4,5,6.

  5. Well, I was left with the same unknowns as you, plus a problem with the third character.

    I missed the last/second to last bit. Instead I was working with: is the seventh character for every input of at least seven letters, and some other character if less than seven. But there was no consistency for those less than seven. Interesting that for every input of at least seven characters, the seventh one ended up being correct.

    cannot constitute a full rule since there is a small number of states with less than seven letters. It is true by pure coincidence (seven and last or second to last characters coinciding in states)

    Why it contradicts the Game Rules: According to the game rules I was not allowed to use anything that does not appear in at least 50% of the cases. There are only 12 commands with less than 7 characters (4,5,6). So I cannot choose one rule for more than 7 characters and another rule for 6 characters or less - that would be cheating the rules. I must use the same deterministic rule for all cases.

    BTW, If the situation were reversed, if one thought he had a rule for less than 7 or less than 8 characters, one could always try it on ABORT and see the result. Doesn't hurt ;)

  6. Well, hell with it, I'll share what I know with the other hackers and see who can get to the bottom of it:

    Each letter is defined differently:

    1) 3rd letter of command

    2) 1 if [unknown 1], otherwise 0

    3) Last letter if command length is odd, otherwise 2nd to last

    4) Number of vowels in command

    5) 1st letter in command if [unknown 1], otherwise 2nd letter

    6) Length of command mod 5

    7) 4th letter in command if [unknown 2], otherwise 3rd letter

    8) Vowel count if [unknown 2], otherwise vowel count + 1

    Here's the values of unknowns 1 and 2 for various commands

    NEVADA: true, false

    MAINE: false, false

    SOUTHCAROLINA: false, false

    HAWAII: true, false

    IOWA: false, true

    LOUISIANA: false, false

    NORTHDAKOTA: false, false

    SOUTHDAKOTA: false, false

    NORTHCAROLINA: false, false

    NEBRASKA: false, true

    MARYLAND: false, true

    NEWYORK: false, true

    OHIO: true, false

    COLORADO: true, false

    INDIANA: false, false

    CONNECTICUT: false, true

    IDAHO: true, true

    UTAH: true, false

    OKLAHOMA: false, true

    OREGON: false, true

    TEXAS: true, true

    ABORT: false, true

    As to what those unknowns can be, I'm stumped...

    Original algorithm for character 3 is not that simple, but it is indeed impossible to distinguish from the proposed algorithm in the values seen so far.

    There are only 7 states/commands (which have not been played) which actually contradict the proposed rule: "3) Last letter if command length is odd, otherwise 2nd to last".

    However, it may be impossible to guess without seeing these states so I assume there is no way the original hash algorithm could be reconstructed - Occam's Razor always favors simplicity.

    However, taking into account that:

    -for WISCONSIN the third letter of the password is S.

    -for WASHINGTON the third letter of the password is G.

    can you deduce the original algorithm for the 3rd letter?

    The rest is correct, or more clearly dependencies of the characters in the password to the unknowns is correct.

    Again as few states have been played, it might or might not be possible to correctly distinguish unknown1 and unknown2 (as is the case with the 3rd character-spoiler above).

    IMHO, this was generally the case in classic cryptography: being able to read at least some of the encrypted messages may count as breaking an encryption algorithm for practical purposes, but does not necessarily be enough to reveal the actual algorithm.

  7. OK, this is it. This had better work, or I'm all out of ideas

    ABORT

    O0T2B0R2

    Password accepted, system shutting down.

    Oh, no, the former Evil Mastermind has cleverly regained control of the system and stopped it. :thumbsup:

    The rest of the states are safe (... for now).

    P.S.: However, in order to reprogram the system, he needs to explain the algorithm so that the system recognizes its master.

  8. Dang! I need some more states blowing up so I get another chance. If I don't get it next time I'll have to go back to the drawing board :angry:

    Evil Mastermind's has gotten back to work as increased attacks on the system could possibly amount to a Denial-of-Service later ... better launch as soon as possible ;)

    OKLAHOMA

    L0M4K3A4

    OREGON

    E0O3R1G3

    TEXAS

    X1S2T0A2

  9. Well I still haven't figured it out but I'll slip this in before anyone else does:

    ABORT

    O1T2A0R2

    I reckon that's got at least a 50-50 chance! :ph34r:

    Command not recognized. Ignoring input.

    (Maybe the coin was not fair? :) )

  10. Evil Mastermind opens the TV and sees live transmissions from South Carolina. This can't be! :unsure:

    Oh, no, reading the logs it seems that the Evil Mastermind has entered a wrong password for South Caroline. Shame on him! :duh:

    The Evil Mastermind enters the correct password:

    SOUTHCAROLINA

    U0A6O3U7

    And quickly checks if the rest of the passwords were correct. Indeed they are.

    ------------------------------------------

    P.S.: Sorry about that! Beginner's mistake :(

  11. You both, of course, got the answer right. What method(s) did either of you use?

    Taking pairs (e.g. A, M) and trying to find words that begin with one and end with the pair.

    Also noticed that if the length is odd then either O or S is in the middle.

    I admit I used a tool for quick browsing more obscure English words (as English is not my first language).

    Crossword solver

  12. NEVADA

    V1D3N1V4

    MAINE

    I0E3A0I4

    SOUTHCAROLINA

    U0I6O3U7

    HAWAII

    W1I4H1W5

    IOWA

    W0W3O4A3

    LOUISIANA

    U0A6O4U7

    NORTHDAKOTA

    R0A4O1R5

    SOUTHDAKOTA

    U0A5O1U6

    NORTHCAROLINA

    R0A5O3R6

    NEBRASKA

    B0K3E3R3

    MARYLAND

    R0N2A3Y2

    NEWYORK

    W0K2E2Y2

    OHIO

    I1I3O4I4

    COLORADO

    L1D4C3L5

    INDIANA

    D0A4N2D5

  13. The Evil Mastermind wakes up to find 3 more targets already selected. Oh well, nothing to do but provide the corresponding passwords and

    OHIO

    I1I3O4I4

    COLORADO

    L1D4C3L5

    INDIANA

    D0A4N2D5

    three more states bite the *radioactive* dust.

  14. Time to unleash new missiles:

    NEBRASKA

    B0K3E3R3

    MARYLAND

    R0N2A3Y2

    NEWYORK

    W0K2E2Y2

    The Evil Mastermind nods appreciatively at the progress so far and ponders where do evil masterminds actually congregate. Do they have clubs or something? If they do, they sure must have a sort of membership challenge so one needs to prove his worth before admission. Yeah, definitely.

  15. I think I've found something. At least it works with all the states so far except IOWA.

    ABORT

    O1T2A0O3

    The Evil Mastermind awakes to find out someone tried to tamper unsuccessfully with the system. Oh well, that happens, it's all good as long as they don't succeed.

    Evil Mastermind slaps himself with a trout for not putting a failed-password counter in the system. Nothing can be done now but live with it. One cannot reprogram the system while it's still running...

    P.S.

    I haven't been at it for long

    :)

    Sure hope it's just a phase.

  16. Evil Mastermind strikes the poor inhabitants of North/South*** and then takes a little break.

    NORTHDAKOTA

    R0A4O1R5

    SOUTHDAKOTA

    U0A5O1U6

    NORTHCAROLINA

    R0A5O3R6

    Edit: Evil Mastermind forgot to use right font, but luckily remembered before getting to bed :)

    ----------------------------------------

    *** Little did they know while growing up (or moving in) that their states are so prone to attacks :)

  17. This game thread continues the tradition of the first two games: and

    One player plays the Evil Mastermind (that's me, replacing the original Evil Mastermind for this game) who nukes the states of the USA 3 at a time, the other players play Hackers who seek to stop the Evil Mastermind. The Evil Mastermind plays by posting commands which activate missile strikes. Each command has a unique password, which is derived from the command by a hashing algorithm. The Evil Mastermind devises a different algorithm at the start of each game, and posts the passwords along with the commands. The Hackers will see the commands and passwords and from this they should try to deduce the hashing algorithm. The Hacker who does this first, and correctly figures out the password to the command "ABORT", stops the Evil Mastermind and wins the game. Anyone can join in at any time as a Hacker.

    Now hashing algorithms can be exceedingly difficult to crack, but there are restrictions placed on the kind of algorithm that the Evil Mastermind can use:

    1) The Evil Mastermind must be able to derive an alphanumeric password of fixed length from any word (password length 8 characters or less, you choose). It doesn't have to be a cipher in the sense that it can be decrypted to the original word, indeed the fixed length makes that impossible.

    2) You must be able to do it in your head, with no external aids, in 40 seconds or less. You may look at the word you are hashing but you should not have to look at the previous letters of the password, since real-life passwords are generally shown as ***** as you type (although you may use previous letters as far as your memory can handle it). It's up to you to ensure that you can do all this. A really classy algorithm is one which fulfils this condition better (quick and easy to perform, in other words).

    3) Although it is quite possible to hold an alphabetic substitution table in your head, and apply it quickly, I'll rule this out because in conjunction with other techniques it's too difficult to crack. Any technique that requires a large amount of information to be memorised in advance is not allowed. Caesar ciphers with a large shift pretty much fall into that category.

    4) Consistency. This is a matter of good sportsmanship. For example, since "ABORT" is the target word, you can't have a rule that comes into play only when the sequence "BOR" occurs. All rules should be general enough that they come into play in at least half of the clues. The algorithm should not be geared toward the specific commands used in this game, but should work on any word.

    Commands

    There are 51 commands, these being the names of US states (used by the Evil Mastermind to nuke another state), plus the word "ABORT" (used by hackers to stop the Evil Mastermind).

    Commands and passwords are all uppercase.

    ABORT

    ALABAMA

    ALASKA

    ARIZONA

    ARKANSAS

    CALIFORNIA

    COLORADO

    CONNECTICUT

    DELAWARE

    FLORIDA

    GEORGIA

    HAWAII

    IDAHO

    ILLINOIS

    INDIANA

    IOWA

    KANSAS

    KENTUCKY

    LOUISIANA

    MAINE

    MARYLAND

    MASSACHUSETTS

    MICHIGAN

    MINNESOTA

    MISSISSIPPI

    MISSOURI

    MONTANA

    NEBRASKA

    NEVADA

    NEWHAMPSHIRE

    NEWJERSEY

    NEWMEXICO

    NEWYORK

    NORTHCAROLINA

    NORTHDAKOTA

    OHIO

    OKLAHOMA

    OREGON

    PENNSYLVANIA

    RHODEISLAND

    SOUTHCAROLINA

    SOUTHDAKOTA

    TENNESSEE

    TEXAS

    UTAH

    VERMONT

    VIRGINIA

    WASHINGTON

    WESTVIRGINIA

    WISCONSIN

    WYOMING

    Game Play

    The Evil Mastermind posts 3 commands at a time, with their passwords. The interval for doing this is undefined, no point in imposing restrictions. The Evil Mastermind chooses the commands, but should generally do requests as soon as possible.

    Each Hacker may make one guess at the password for "ABORT" each time the Evil Mastermind posts commands. If someone makes multiple guesses in between clues, only the first one counts, but if they make a mistake and correct it, the Evil Mastermind can accept the correction.

    There is no need for spoilers when guessing the password, although please use spoilers if you reveal the algorithm.

    The first one to get the password for "ABORT" wins.

    P.S. Alternatively if you've cracked the algorithm you can just use it to blow up more states if you're that way inclined (**per original Evil Mastermind's rules!)

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