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Ken Thompson's Unix Password

leahneukirchen.org

21–30 of 665 posts

Re: Ken Thompson's Unix Password

#22

A slight nitpick with the article - `p/q2-q4` (more commonly written as "1. d4" in modern times) is not the Closed Game, it's just the first move of it. There are many, many other lines after 1. d4 besides just 1. ..d5, most of them quite open!

It is the beginning of the closed game, which is what the article says. Seems like a vacuous nitpick.

Uh, okay, technically true, touché.

But it's "the beginning" of roughly 50% of all chess games ever played. It seems very strange to call out one particular line it _might_ end up being the beginning of.

It's also "the beginning" of game 2 of the 1929 Bogoljubov-Alekhine world championship match, among millions of others, after all.

Re: Ken Thompson's Unix Password

#23

I'm shocked at how well the old hashing stood up; sure, it's totally crackable today, but a well-picked password still took 4+ days to crack on modern hardware, which is remarkable. (Granted, it doesn't sound like they did anything fancy like throwing a hundred cloud instances at it or something; I'm not saying you should use DES today:) )

30 years ago I cracked everyone’s Unix password on an old Sun computer.

It didn’t take long because everyone had a password that was in the dictionary.

Needless to say, people were not happy with the messenger.

Re: Ken Thompson's Unix Password

#25
post #21

I'm disappointed that it followed a pattern like that, since that's supposed to make it easier to brute-force guess.

It seems likely that someone will write an archaic chess notation pattern engine into the crackers now that this has been discovered and shared widely.

Re: Ken Thompson's Unix Password

#26
post #8
post #7

>Since the DES-based crypt(3) algorithm used for these hashes is well known to be weak (and limited to at most 8 letters) >ZghOT0eRm4U9s:p/q2-q4! How is that 8 letters?

The part before : is the hash, the part after is the cracked 8 character password.

still 13 characters...

edit: LOL, I guess I'm a little dumb today

Re: Ken Thompson's Unix Password

#29

A slight nitpick with the article - `p/q2-q4` (more commonly written as "1. d4" in modern times) is not the Closed Game, it's just the first move of it. There are many, many other lines after 1. d4 besides just 1. ..d5, most of them quite open!

It is the beginning of the closed game, which is what the article says. Seems like a vacuous nitpick.

Pedantry might as well be correct: calling q2-q4 "the beginning of a closed game" hides the fact that it's also the beginning of many other validated openings: https://en.wikibooks.org/wiki/Chess_Opening_Theory/1._d4

Advancing the queen's pawn 2 squares is a very common first move in chess at all levels. It's disingenuous to call this the beginning of any one of the specific possible openings in the above list.

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