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Passwordle

rsk0315.github.io

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Re: Passwordle

#201

Post by [deleted] »

mlyle wrote: post #107
moritonal wrote: post #7

There is like... four people I know I could send this to who'd laugh, it's so niche. Yet I also laughed out loud when I got how conventionally impossible it is.

Is it? 6 guesses and I have 14 hex digits (56 bits) of the hash, along with knowing the population counts for all the numbers. This is enough to run a password cracker and determine the plaintext if it's a readily guessed password. Sure, it breaks conventional use of rainbow tables, etc, but... edit: Eh, 14 characters. OK, that's pretty resistant to anything other than debugging.

[deleted]

Re: Passwordle

#202

Post by lazide »

mlyle wrote: post #136
residualmind wrote: post #120

Earlier quoted context omitted.

Are you sure thats how evenly distributed hash algorithms work? change one letter of your string, or just make it longer or shorter - none of your green fields will stay.

> Are you sure thats how evenly distributed hash algorithms work? change one letter of your string, or just make it longer or shorter - none of your green fields will stay. True. But still, I know the vast majority of words in my dictionary don't match those two green fields after hashing, and can be eliminated from further consideration as the password.

The password is not a dictionary word, it’s randomly generated though?

Re: Passwordle

#203

Post by mlyle »

lazide wrote: post #202
mlyle wrote: post #136

Earlier quoted context omitted.

> Are you sure thats how evenly distributed hash algorithms work? change one letter of your string, or just make it longer or shorter - none of your green fields will stay. True. But still, I know the vast majority of words in my dictionary don't match those two green fields after hashing, and can be eliminated from further consideration as the password.

The password is not a dictionary word, it’s randomly generated though?

Yes, it's a randomly generated string with ~90 bits of entropy.

After one guess, I know many fewer of those values could work. Unfortunately, the best known way to test this is to enumerate all of them.

14 character random strings are out of reach; 11 character strings you can enumerate & test them all with a lot of computing.

Re: Passwordle

#205

Post by selestify »

mlyle wrote: post #194
gitgud wrote: post #175

Earlier quoted context omitted.

This is the best description of why it's completely infeasible to make a system to guess it. It would be only be possible if the password length was below a certain threshold (maybe 30 characters) beyond that limit, there wouldn't be enough atoms in the known universe in order to store every hash/password combination.... making it physically impossible....

In passwordle, the input is a 14 character password made up of letters, numbers, and punctuation, chosen with some bias. There's less than 92 bits of entropy (the bias shaves off a few bits of effective entropy but I'm too lazy to calculate it). That is-- out of the range of current brute force, but if it were just a few characters shorter, it could be attacked with this oracle technique no problem.

How would the oracle technique help at all? Like the other commenter said, they could just give you the hash upfront, and you'd still be stuck with bruteforcing the entire space of characters.

Re: Passwordle

#206

Post by mlyle »

selestify wrote: post #205
mlyle wrote: post #194

Earlier quoted context omitted.

In passwordle, the input is a 14 character password made up of letters, numbers, and punctuation, chosen with some bias. There's less than 92 bits of entropy (the bias shaves off a few bits of effective entropy but I'm too lazy to calculate it). That is-- out of the range of current brute force, but if it were just a few characters shorter, it could be attacked with this oracle technique no problem.

How would the oracle technique help at all? Like the other commenter said, they could just give you the hash upfront, and you'd still be stuck with bruteforcing the entire space of characters.

> How would the oracle technique help at all?

If they give you the hash upfront (or this oracle), you can test passwords offline without using up a limited number of guesses. It may be very computationally expensive to brute force the space, but the information is there.

If they don't, you get 10 guesses, and you have effectively no chance of guessing the password.

Re: Passwordle

#207

Post by paledot »

throwaway6532 wrote: post #176
mlyle wrote: post #160

Earlier quoted context omitted.

92 bits of entropy, and the first guess peels off about 14 bits of it. Subsequent guesses a little less. The annoying thing is, you still have to search that whole space to find the password. But after 9 guesses, you can solve offline for the character string... it's just very expensive.

Could you do it with a rainbow table?

I mean, your rainbow table would need to contain 2^92 entries...

Re: Passwordle

#209

Post by mleonhard »

moltenguardian wrote: post #58

Someone more capable than I should make the final form of this: No green or yellow feedback is provided, but only the timing information used to calculate it. If cryptographers are serious about side-channel attacks, why not show off the danger using no-information Wordle? (edit: Absurdle was taken)

Timing of SHA-256 reveals only the length of the input.

Re: Passwordle

#210

Post by selestify »

mlyle wrote: post #206
selestify wrote: post #205

Earlier quoted context omitted.

How would the oracle technique help at all? Like the other commenter said, they could just give you the hash upfront, and you'd still be stuck with bruteforcing the entire space of characters.

> How would the oracle technique help at all? If they give you the hash upfront (or this oracle), you can test passwords offline without using up a limited number of guesses. It may be very computationally expensive to brute force the space, but the information is there . If they don't, you get 10 guesses, and you have effectively no chance of guessing the password.

Ah, I see what you mean. Yes, if you don't even have the entire hash, you're kind of out of luck.

> It may be very computationally expensive to brute force the space, but the information is there.

If the password is long enough, it will take longer than the heat death of the universe to brute force the space. So in practice, brute forcing secure passwords might as well be impossible.

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