[Guest]

One player plays the Evil Mastermind (that's me) 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 either one third of the clues posted at any given time, or 10 clues posted. 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 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" for 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!)

PENNSYLVANIA = N6432347

MICHIGAN = I4964346

KENTUCKY = E5297679

Edited November 11, 2010 by Vineetrika

[araver]

Nice

...getting to work now

[Guest]

ILLINOIS = L4976568

TENNESSEE = T3852111

TEXAS = E5182516

[Guest]

NEVADA = E5175827

ALASKA = A3741814

VIRGINIA = I5176558

[Guest]

INDIANA = N4965461

SOUTHDAKOTA = U6319925

MONTANA = O5287683

[Guest]

Hmm, this is difficult! I can't seem to make any inroads. I'd like the short ones please: OHIO, IOWA and UTAH

[Guest]

OHIO = H4147282

IOWA = W5727359

UTAH = T4937271

[araver]

To find the first letter, count distinct vowels, take the letter on that position.

[Guest]

SOUTHCAROLINA = T6434682

NEWYORK = E5298714

NEWHAMPSHIRE = W5299124

[plainglazed]

Still searching for direction. Can we do without North Carolina, West Virginia, East Jesus? Oh, that's just two. Uhm New Mexico?

[Guest]

NORTHCAROLINA = R6319135

WESTVIRGINIA = S6422236

NEWMEXICO = W5219925

[Guest]

ARIZONA = I6432483

NEWJERSEY = N3841999

IDAHO = A5358386

[Guest]

ALASKA        = A3741814

ARIZONA       = I6432483

IDAHO         = A5358386

ILLINOIS      = L4976568

INDIANA       = N4965461

IOWA          = W5727359

KENTUCKY      = E5297679

MICHIGAN      = I4964346

MONTANA       = O5287683

NEVADA        = E5175827

NEWHAMPSHIRE  = W5299124

NEWJERSEY     = N3841999

NEWMEXICO     = W5219925

NEWYORK       = E5298714

NORTHCAROLINA = R6319135

OHIO          = H4147282

PENNSYLVANIA  = N6432347

SOUTHCAROLINA = T6434682

SOUTHDAKOTA   = U6319925

TENNESSEE     = T3852111

TEXAS         = E5182516

UTAH          = T4937271

VIRGINIA      = I5176558

WESTVIRGINIA  = S6422236

[araver]

Can we get OREGON, NORTHDAKOTA, MISSISSIPPI?

[Guest]

OREGON = R4976948

NORTHDAKOTA = O5286557

MISSISSIPPI = M3852111

[Guest]

MASSACHUSETTS = S6319135

WISCONSIN = I5187779

CALIFORNIA = L5211235

[Vipe195]

I believe the first two letters are...

Abort

B5

Thanks for the tip araver.

Edited November 13, 2010 by Vipe195

[Guest]

What's this? 30 states blown up and no answers? This won't do at all, I shall have to do something about this.

ABORT

B5292517

[Guest]

Password accepted. Logic please ?

[Guest]

Password accepted. Logic please ?

Why certainly.

Can't be having with people laying waste to the USA. That's my job.

The first letter is as araver pointed out. This is then used to seed the random number generator of your PC when then spews out 7 digits from 1 to 9.

Seems a shame to put a stop to the efforts of those trying to do this. It's a good puzzle really. They can solve it themselves

[araver]

my logic works better

[Guest]

Anyone else cracked this yet?

The reason I ask is because I was thinking of doing another CtC, but wondering where to pitch the difficulty level.

In all previous CtC's I've done, I have given some thought to how people are going to solve it, and tried to leave a "way in" or at least give the hackers a fair chance. Vineetrika's offering here seems to have given less consideration to how you're going to solve it. The 1st letter is a bit of a start but not much of one really. As a result, I actually found this to be a far more satisfying challenge, I really enjoyed bashing away at it. In the end it was a great puzzle, so thanks for that Vineetrika. I've also noticed that in my algorithms, people have sometimes picked up on clues I did not intend to leave. So maybe I should post one with no intentional weaknesses. However, if nobody else can crack this, I'd be wasting my time if I were to up the ante from here. Come on guys, this is solvable, show me you can do it!

[araver]

Anyone else cracked this yet?

Come on guys, this is solvable, show me you can do it!

I've cracked the second character a little after you posted the ABORT command, but since there was no longer any pressure, I admit I kind of left it alone for a while

Select next letter in command (position n+1, where n = number of distinct vowels).

If this letter is <= M then x=0, else x=1.

Write n + 2 + x in password.

[Guest]

araver, when you can solve the second character, what is stopping you from solving the rest ?

[araver]

araver, when you can solve the second character, what is stopping you from solving the rest ?

As I said, since there was no pressure I gave the problem some rest as I was blocked going around in circles and trying the same things over and over again. I will give it another try with a fresh perspective

[araver]

Hmmm .... I only found a far-fetched explanation.

@Vineetrika, is it making sense?

First character

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

n = number of distinct vowels

The n-th letter in command is the first character of the password.

Second character

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

If (n+1)-th letter in command is <=M then x=0 else x=1

n+2+x is the second character in the password

Third character

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

If (n+2)-th letter in command is <=M then y=0 else y=1

If (n+2)-th letter in command is the first letter of the command (considering that command is read continuously from left to right) then subtract number of letters) (4 in case of IOWA) i.e. alpha= - nrletters else alpha =0.

(n+2+x)+(n+3+y) + alpha gives a number. If it is equal or greater than 10, subtract 9 from it. (sort of a weird modulo 9?)

Fourth character

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

If (n+3)-th letter in command is <=M then z=0 else z=1

If (n+3)-th letter in command is the first letter of the command (considering that command is read continuously from left to right) then subtract number of letters (5 in case of IDAHO, 4 for UTAH and OHIO) i.e. beta= - nrletters else beta =0.

(n+2+x)+(n+3+y) + (n+4+z)+beta gives a number. If it is equal or greater than 10, subtract 9 repeatedly from it until you arrive in [1..9]. (sort of a weird modulo 9?)

EDIT: Also, if you've passed the beginning of the command add 1 before subtracting 9's (case of IOWA).

Edited November 20, 2010 by araver