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Engineyard SHA Contest Leaderboard I threw together
- twism 17y agothe rules says you can "append up to 5 characters" but you consider entries with less than 5 optional characters invalid.
- jazzychad 17y agoNo, there are several listed with less than 5 extra characters. It's just that most people are using all 5.
- bcl 17y agoGood job! Could you add a timestamp and option to sort by it? (I know, feature creep!) ETA: I also find it interesting that the lowest score from those not using the optional 5 random chars is currently 38. All the lower ones use random chars.
- jazzychad 17y agoThought about it, but the two systems I used to compile the data are showing different timestamps (almost like a timezone mismatch) so now it's too late to fix them. I do have the "latest 10 entries" as a compromise.
- deleted 17y ago[deleted]
- JeremyChase 17y agoThere is a practical reason for this depending on your algorithm. In mine it was much faster to change the last 5 characters instead of changing the entire string. I saw about a 50% performance improvement by creating a fixed set of 12 words, and altering the last 5 characters. Then updating the 12 words when necessary.
- philfreo 17y agoRight now you're showing duplicate entries (the same entry of value 31 is showing from two people)
- jazzychad 17y agoThat's because somebody just copied and pasted somebody else's entry. The system is working as intended. I'm sure Engineyard will catch it in their judging (or so I hope).
- 0wned 17y agoTwitter accounts with "private" updates do not show up on the public timeline... my three submissions are nowhere to be found and they do validate.
- deleted 17y ago[deleted]
- 0wned 17y agoI'm a twitter virgin. Never tweetted before today's contest. My best score was 36. No big deal.
- brown9-2 17y agoKind of interesting or funny that these entries are pretty close to the top of the standings: 31 d241c4b4dd38aacb197c8e48e9f8488264e39a83 bUGs BUgs bUGS bUgS bLAnk BlAnK BlANK BLank buGS bugS bUGS bUGs dCao2 32 334945bffdd1000f1d198e02497188a2b17f1991 cOWs cOwS cOwS cowS DIRtY Dirty DiRTY DIrtY cOWS Cows CoWs Cows owjo0 (assuming the score are correct)
- mrduncan 17y agoIt looks like "hashbreaker" and "CodingCrypto" are both running through nearly the exact same word sets. Either they are from to different people using the exact same algorithm or (what I suspect is more likely) they have created multiple twitter accounts to get around the submission limit. hashbreaker bUGs BUgs bUGS bUgS bLAnk BlAnK BlANK BLank buGS bugS bUGS bUGs dCao2 CodingCrypto BugS BUgs buGs BUgs bLANK Blank bLanK BlAnk BuGs BuGs BUGS bUGs FcBkw CodingCrypto cOWs cOwS cOwS cowS DIRtY Dirty DiRTY DIrtY cOWS Cows CoWs Cows owjo0 hashbreaker CoWS coWS CowS cOWS DiRTY DIrtY DirTy DIRtY COWS COWS cOwS cOWS bvpDq Edit: Also, accounts had their first tweets on the 19th.
- mrduncan 17y agophubbard has a very similar submission as well: BUgs bUGS bUGs bugS BlaNK BLanK blANK bLaNK BugS BUgs BuGs bUgs liwcC Based on his Twitter account I'm a little more inclined to believe that they are indeed separate people all using the same algorithm. Edit: This appears to be their info based on the submission by nkurz - http://news.ycombinator.com/item?id=717174 http://news.ycombinator.com/item?id=717174
- gojomo 17y agoDisregarding the last 5 characters, the 'bugs blank' and 'cows dirty' strings are exactly 64 characters (512 bits) long, as are many of the other leading entries. Savvy teams are checkpointing the hash at the 64 character point, then rerunning it from there with alternate endings.
- jodrellblank 17y agoWhat do you mean by 'checkpointing the hash'? How far can you go into an SHA1 calculation and then change the input and have your calculation be useful?
- gojomo 17y agoThe function as applied to a stream of bytes has a certain amount of internal state. You could at any moment take a snapshot of the entire state, and from that point, feed it different suffixes of the same previously-fed data. In this way, you calculate many final hashes without always repeating the redundant part (the shared prefix). For a concrete example, consider let us say you wanted to take the SHA1 of the input that is 1MB of 'a' followed by an 'a', and then 1MB of 'a' followed by a 'b', etc. You don't have to run the SHA1 function over 'a...aa', then reset from scratch and run it over 'a...ab'. You can run it over 'a...a' without then feeding it the final byte or performing its final steps, snapshot its state (which is only some small multiple of its final output size), and then quickly calculate 'a...aa', 'a...ab', 'a...ac', etc. without redundantly feeding the identical 1MB prefix in each time.
- theblackbox 17y agoWould the contest have been any easier had one made the (dubious) assumption that the "passphrase" encoded would likely be a valid sentence? I've not tried any crypto work before but this has really grabbed my interest. It just occurred to me however, that discarding lines of inquiry leading down the "BuGS bugs bUgs BUGs BLAnK BlAnK....." route in favour of something that made more sense grammatically could be a good tactic to save time?.... or it could just increase the overhead in generating the next hash?...
- eru 17y agoUnless you found the exact sequence, the difference between hashes won't tell you how close you are.
- theblackbox 17y agoI don't see what you mean by "the difference between hashes won't tell you how close you are" .... isn't that the whole point of this competition? Say for instance you coded four stages: 1/ Generating a list of strings for analysis 2/ Parsing that list for sentences that made sense 3/ Hashing these sentences 4/ Comparing the hashes generated with the one being sought to me it just looked as though a lot of gibberish was analysed because there is a lot more entropy than order to sift through and nobody tried step 2... does my logic make sense or am I getting mixed up and not really seeing the bigger picture?
- eru 17y agoSuppose the hash for a specific phrase was completely random, but fixed. (Which is not too far off for a cryptographic hash-function.) So unless you want to find the exact sequence, it does not matter whether you candidate strings make sense or not. And since the search space is so large, people just gave up on finding the exact sequence. They just use a lot of cycles to find any sequence, that is close in hash.
- jodrellblank 17y agoThere's no benefit in trying step 2 because the gibberish input is as likely to be a close match as a sentence that makes sense. A sentence that starts 'Be' (001000010...) and the same sentence changed to 'He' (001001000...) would produce very different hash results by the Avalanche Effect ( http://en.wikipedia.org/wiki/Avalanche_effect http://en.wikipedia.org/wiki/Avalanche_effect ). So having similar letters in a similar order or in similar positions, or using similar length words, wont help. Isn't that the whole point of this competition? The point was to get a hash with a similar quantity of 0 and 1 bits in the output as their hash, not to guess their sentence (they said what it was).