[Guest]

While you're still puzzling over the algorithm to ,&do=embed' frameborder='0' data-embedContent> here's a bit of fun that occurred to me while doing the same. Rather than the mean unsolvable algorithm I was threatening, this should be a piece of fluff which will no doubt be solved rather quickly. But it contains a couple of ideas which I thought were quite cute, so I couldn't resist doing it.

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) What it is

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) Simplicity

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) No memory feats

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 may 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 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!)

- Host: octopuppy - Winner: fabpig

- Host: octopuppy - Winner: araver

- Host: araver - Winner: octopuppy

- Host: dawh - Winner: octopuppy

- Host: octopuppy - Winner: Vineetrika / araver,

- Host: Vineetrika - Winner: octopuppy

- Host araver - Winner: octopuppy

Update

49 states down, only 1 to go! Last chance to stop me going the distance...

Here are the clues so far:

ALABAMA

EOEDBQCB

ALASKA

EOEWMBDM

ARKANSAS

DVMBQVEW

CALIFORNIA

FEOLJSTO

COLORADO

DPNQSDEP

CONNECTICUT

EQOQGEXM

DELAWARE

GGPCZETH

FLORIDA

JORVMGEH

GEORGIA

KFPUKMCH

HAWAII

KEXDLLLC

IDAHO

JFBKRLED

ILLINOIS

JNPMPQKU

INDIANA

LRGLEPBJ

IOWA

LRYBJPAC

KANSAS

NEPUBTNE

KENTUCKY

OFQUVDNC

LOUISIANA

MPVJTJDR

MAINE

NDLRFQCK

MARYLAND

PETZNBQE

MASSACHUSETTS

QCUUBDKX

MICHIGAN

OKEIJJEP

MINNESOTA

OKOQGUQX

MISSISSIPPI

QMWWMWWM

MISSOURI

QMWWSYTK

MONTANA

OQOVBQEN

NEBRASKA

RFEVCULD

NEVADA

RFXBFBQG

NEWHAMPSHIRE

PHYIDOTW

NEWJERSEY

RFANFUVG

NEWMEXICO

QGZOHYJD

NEWYORK

RFAAQSNR

NORTHCAROLINA

RSTXJEBU

NORTHDAKOTA

RSTXJHCL

OHIO

PKLRRLMS

OKLAHOMA

ROOEJQPE

OREGON

RVFJRRST

PENNSYLVANIA

QIPOTBMX

RHODEISLAND

SKREIMWO

SOUTHCAROLINA

VRXUKFET

SOUTHDAKOTA

VRXUKEDO

TENNESSEE

WGOQGUUH

TEXAS

VHYDVUIA

UTAH

XUDLYWEJ

VERMONT

ZFUOQOVZ

VIRGINIA

WJUKMPKB

WASHINGTON

YBTKLRIX

WESTVIRGINIA

YHVUXKSJ

WISCONSIN

YKUEQOTJ

WYOMING

YZPQMPHA

[Guest]

And away we go

CONNECTICUT

EQOQGEXM

ILLINOIS

JNPMPQKU

KENTUCKY

OFQUVDNC

[araver]

No clue so far...

Can we get the little ones? UTAH, IOWA, OHIO? (If there's no one around that is).

EDIT: If anyone has other choices, please do

Edited November 27, 2010 by araver

[plainglazed]

how 'bout - Alaska, Alabama, Kansas, Arkansas - KABOOM!

[Guest]

Here you go...

IOWA

LRYBJPAC

OHIO

PKLRRLMS

UTAH

XUDLYWEJ

...and that's all from me for tonight

EDIT: Oh, just saw plainglazed's requests. Well maybe I'll do those too.

[Guest]

Only 3 at a time, so I'll give you Alaska in the morning if nobody's aborted me in the meantime!

ALABAMA

EOEDBQCB

ARKANSAS

DVMBQVEW

KANSAS

NEPUBTNE

[Guest]

I'm back! Maybe these will help...

ALASKA

EOEWMBDM

NEVADA

RFXBFBQG

NEWYORK

RFAAQSNR

I kind of wish I was on the other end of this one. I think it would be fun to solve, I really do.

[Guest]

FLORIDA

JORVMGEH

LOUISIANA

MPVJTJDR

MINNESOTA

OKOQGUQX

[wolfgang]

I noticed this( it may help!)

see the code for Connecticut.......EQOQGEXM

and the code for Minnesota.........OKOQGUQX

both have(after the first two letters)three common letters(OQG)which may have a connection to

(nne)in both States.

[Guest]

NEBRASKA

RFEVCULD

PENNSYLVANIA

QIPOTBMX

WASHINGTON

YBTKLRIX

[araver]

I'd like NORTHDAKOTA, MONTANA, TENNESSEE.

[Guest]

An interesting selection. Montana?

NORTHDAKOTA

RSTXJHCL

MONTANA

OQOVBQEN

TENNESSEE

WGOQGUUH

[araver]

An interesting selection. Montana?

I was following a hunch and hoped to verify it by the time I get MONTANA.

Did not work as planned though, it just blew in my face

EDIT: Still worth a try, though.

Here's what I would have tried:

EESTXDFR

Edited November 28, 2010 by araver

[Guest]

EDIT: Still worth a try, though.

Here's what I would have tried:

EESTXDFR

Password rejected, armageddon continuing as usual.

DELAWARE

GGPCZETH

MICHIGAN

OKEIJJEP

OREGON

RVFJRRST

[araver]

Thought so.

Next GEORGIA, VERMONT, WESTVIRGINIA, please.

[Guest]

As you wish. Time to compile it all in the OP I think!

GEORGIA

KFPUKMCH

VERMONT

ZFUOQOVZ

WESTVIRGINIA

YHVUXKSJ

[Guest]

INDIANA

LRGLEPBJ

NEWHAMPSHIRE

PHYIDOTW

SOUTHCAROLINA

VRXUKFET

[Guest]

MARYLAND

PETZNBQE

MISSOURI

QMWWSYTK

NEWMEXICO

QGZOHYJD

[araver]

I'm still pondering a few to get an accurate shot at ABORT, but if you get around before I do,

please give MAINE, MASSACHUSETTS and MISSISSIPPI a try.

Thank you.

[Guest]

Here you go!

MAINE

NDLRFQCK

MASSACHUSETTS

QCUUBDKX

MISSISSIPPI

QMWWMWWM

[Guest]

Wow, didn't think this one would last so long!

CALIFORNIA

FEOLJSTO

HAWAII

KEXDLLLC

WISCONSIN

YKUEQOTJ

[Guest]

NORTHCAROLINA

RSTXJEBU

RHODEISLAND

SKREIMWO

VIRGINIA

WJUKMPKB

Only 8 states left!

[araver]

More like a "Function Menace" than a "Phantom Function".

Seriously, my brain is telling me it's not properly wired for this particular code, so you might wanna delay it for other Hackers to join in.

It hasn't been exactly a peak in activity for a while now (Thanksgiving and all).

[Guest]

More like a "Function Menace" than a "Phantom Function".

Seriously, my brain is telling me it's not properly wired for this particular code, so you might wanna delay it for other Hackers to join in.

It hasn't been exactly a peak in activity for a while now (Thanksgiving and all).

Yes I am getting the feeling it's just you and me!

Good thinking, I'll spin out the last 8. Don't lose heart, I'm pretty sure this is doable if you look hard enough. After your last one, I thought it would be a doddle. OK, it's not exactly the same, but still....

[Guest]

Yes I am getting the feeling it's just you and me!

Good thinking, I'll spin out the last 8. Don't lose heart, I'm pretty sure this is doable if you look hard enough. After your last one, I thought it would be a doddle. OK, it's not exactly the same, but still....

Of course, you were the one to solve the last one...

Also, as araver said, I haven't had a chance to examine this at all. So I don't know if I could solve it or not. I'll get to it soon, if I can.

[araver]

Yes I am getting the feeling it's just you and me!

Good thinking, I'll spin out the last 8. Don't lose heart, I'm pretty sure this is doable if you look hard enough. After your last one, I thought it would be a doddle. OK, it's not exactly the same, but still....

Coming clean with what I have so far ... some thoughts of cryptanalysis.

Can be read independently of the last code you're referring too (no spoiler for that in here).

My current hypothesis is that the first character is shifted +f1(command) than the first character in the command. where f1(command)=1,2,3 or 4.

Searching for a function that predicts function f1 has yielded so far the following thoughts:

- (Sure) first three characters in command are not enough to determine a first character in password (counter-examples: NEWMEXICO,NEWYORK, NEWHAMPSHIRE)

- (Sure) last character in command does seem to play a role (e.g. NEVADA, NEBRASKA start the same)

- (Sure 99%- Occam's Razor) second character in command does not seem to play a role (e.g. NEVADA, NEBRASKA, NORTH* start the same, despite the change in second character)

So, I'm pretty sure (for a while now) that f1 depends on first and last character. However, I did not find a simple f1 such that:

f1(A,A)=4

f1(A,F)=4

f1(A,G)=4

f1(A,N)=4

f1(A,I)=3

f1(A,M)=2

and so forth

It also seems commutative (f1(O,N)=f1(N,O)=3).

On the other side(s):

- normal crib finding and matching did not succeed (as they usually do if the same type of function is used for each letter in password).

- predicting f1(T,A) is not trivial without a strong notion of what f1 is so there's no simple brute-force even for the first character.

- no shift (start point choosing) appears to be in play, neither visible in how the password looks (sure of that), neither in how the password is computed (almost sure)

- all the differences are 1,2,3,4 which suggest either modulo 4 or bitwise operations modulo 2 (none satisfactory so far).

- either order does play a role OR the rounds of the function accumulate e.g. crib KANSAS in ARKANSAS yields different outcomes, yet the first-order delta sequence between the outcomes is -1 2 0 1 0 in KANSAS and 1 -2 0 -1 0 in ARKANSAS which suggest a sign-change

And that's about all I have ATM.