ZK HACK IV - Puzzle F2 Recap

Transcript

hello okay nice to see this nice crowd for the most astute members of the audience you will have noticed that I am not Anna this is me gay I'm actually taking over uh replacing Anna for today she had a prior commitment we hope to see her at the end of the session but I will be with you for this introduction on the next 15 minutes uh let's go for it actually because we on a tight schedule uh so welcome welcome everybody to this session number three of ZK hack 4 uh oh I'm sharing my screen so a reminder for those who were not with us

for the first two sessions sadly uh we are zck uh having a lot of different type of projects that we try to map on this uh diagram uh the two main entrance Gates I would say for Z hack are the website on the Discord so yeah check out our website that's maybe where you were able to subscribe to Z hack in the first place the hack for online we also have a Discord if somehow you manag not to join us already please follow the QR code this is where we host all the discussions about the events Z h four but not only where we share also learning resources where you can ask

questions this is really the the place of the village where the zck community can gather and discuss about zck 4 so our series of event to follow uh everything that's going up getting our updates uh and notably getting the notifications for all the puzzles the new puzzles that we will announce at the end of this session for instance please make sure you go to zik haak for websites you will also have the schedule the replays of the workshops everything that we do during this four weeks events so what are we doing here we are having weekly workshops so we had the ZK Jon decoder two weeks ago we had an

amazing Workshop by risk zero team uh last week this week we will have polygon hosting the thir Workshop so please stay with us it will start in just a little bit there these workshops we also have a CTF like puzzle competition with the puzzles uh prepared with Love by the geometry research team uh and also you will compete for prizes and Glory if you're into that type of stuff last but not least uh will happen next week next week ZK jobs fair so we will host that on gather toown um a virtual world online where you can actually walk around meet your Z hack for peers and

also uh meet uh some of our sponsors who have posted uh jobs offers online with the help of our media partner zero knowledge so that's anas podcast uh another Point very important one so the question keeps popping up in the Discord um do you have replays for the workshops yes we do we do they're all published on the Zero knowledge YouTube uh Channel channel so make sure you're actually subscribed to get the notification when a new video is posted we have a dedicated playlist the ZK hack playlist where we post all the recordings of the sessions so the puzzle announcement but also and mostly the

workshops we try to do it uh if not tomorrow the day right after so where are we at in the schedule so as I said we had uh the workshop by risk last week with the Pu puzzle F2 that started this actually ended the submission today at noon thank you for all the participants uh we will also have as I mentioned the polygon Workshop right after it will last until 655 more or less where the third puzzle will be announced the third and last puzzle will be announced by uh possibly an animal or two I don't know that's

going to be the surprise oh so don't miss next week the last session that's going to be the the last one so we will have the final introduction and then a ZK panel hosted by Anna uh with the topic being what's it really like working in ZK somehow a nice introduction uh for the GK ZK jobs spare that will happen at the end from 7 PM UTC and between that there will be also a very important moment with the third puzzle winners announcements and the final prizes announce ment so before jumping into um sharing a bit more about the the puzzle I really want to say thank you to all the

participants we actually had as many submissions that for puzzle F1 uh plus one some people did not submit for F2 but did for F1 some people did submit only for F2 uh I want to actually thank them so megaloblast ZX RC not not Ru a12025 n me you work up until 5: a.m. to submit thank you for that man it was great Intel DDS and I want to have some kind words for amid Resa who actually submitted just a little too late but you won't get any point for this submission but we wanted you to be on the on the leader board so well done people that was great and we hope as much if not more participation for the last

puzzle and before announcing the the prizes I'd like to welcome on stage a member of the geometry research team that will tell us a bit more about puzzle F2 let's see under what forms it comes up hello hey there how are you this nice cat yes all right so let's talk about puzzle F2 also called super VM um so the puzzle was about a signature scheme that is very important

in some situations that we know in production and specifically validator sets like to use multi signatures and aggregatable signatures and BLS are BLS signatures are really good for that because you can compress many signatures into one um and sometimes what you need to do in order to prevent Keys canceling each other when you aggregate them you need to make sure that everyone that submits their own public key they then need to also prove that they know the secret behind the publicy and the the problem in the

puzzle as many of you have discovered was that the pro proof of knowledge was done in a bad way and it's one of my favorite topics it's called malleability so that you can take one proof of knowledge and transforming it into a proof of knowledge of another key without even knowing and the original key and uh yeah all of you that solved it correctly managed to exploit the linear linear properties of this specific proof of knowledge and and um the fix that would have solved it is again described very

well in the zash security analysis uh where you just need to use hash to curve correctly um and yeah I see that some people got it really really quick some people got it throughout the week um I even saw a solution that I didn't expect which someone canel all the keys and got to a key that is actually zero and they also uh they also left when the signature just verified with the zero signature which was which is pretty cool um and uh and yeah I think one thing

that confused people we've seen that sometimes people didn't understand that they had to modify the message to their GitHub username so what we decided to do is to just accept uh all the solutions that also included the the way to solve the puzzle okay yeah we saw a discussion on the Discord yeah exactly exactly and yeah when you obviously solved it and it would just be changing the message like one line change to your username we we understand that you solve it no worries okay we have Z hack yes so so yeah good job everyone and I hope you enjoyed it

and yeah feel free to discuss it later on and learn from the write ups that people wrote We got some really good write ups so yeah g yeah please please stay with me for the for the Winner's announcement we're going to jump to that but yeah as you were saying Kobe we know that even after the submission time was passed for puzzle one people kept chatting about puzzle one please do the same for the puzzle two I mean that's also the purpose of this to keep people are talking about the different ways to solve the problem so before jumping into the winnner announcements I want to thanks uh zkv they are the generous partner that will uh reward the winners with these prizes so 500 usdc for the third

place 700 usdc for the second month 1,000 usdc for the quickest to crack the puzzle with 300 usdc for the best write up let's jump into it drum roll at the third place place for puzzle two this week we have William bouro congratulations as you can see very quick submission after the first one well done at the second place drum roll we have NEOS well done sir thanks for the claing on the chat yeah that's that's one wrong up for for

this week so well done sir and at the top price and the winner of this week puzzle is Ben anesco congratulation actually uh what was way further down the ranking last week so it's nice to see new name new names at the top so thank you very much to all the participants and congratulation last but not least we want to congratulate the best write up from a friendly neighbor member of the community of Zak that most of you guys know Thor 314 well done made for the great write up yes I think you did not

expect that so well done we will publish all the all the results and the updated leaderboard spoiler alert we have a new leader it will be published in a bit on the zik hack website you just need to give me 10 minutes okay great thank you Kobe and yeah so for the prices we will actually send all the rewards uh towards the end of the session so at at the end of the of the four-week series of events we'll also have some more cool gifts and prizes to come so stay tuned we'll have some surprises for you uh for instance this nice nfts so check out the collection on opy we

didn't have I think we didn't have any new sales this week but uh they reward the best cryptographers in the space and actually you can the you can check their wallets they are amazing cryptographers that are the owner of these nfts I want before jumping to the workshop to thank our amazing Partners so name namely risk zero polygon zero knowledge podcast geometry research and zkv thank you as well to our community sponsors Lambda class Aztec trapdoor Tech Neil Foundation puzzle. online Aptos and starware thank you very much

uh they're obviously the ones making zik hack for possible and one last thing don't forget about the ZK jobs Fair happening last week on gton we communicate uh a bit more about this uh towards throughout the week uh so make sure you keep that on your radar you put that in your calendars make sure you follow the website as well with all the latest updates regarding the link and actually we will communicate that link at the end of the last session next week so make sure you stay tuned and you actually register to this last session that's where you will be able to actually apply on discuss all the different jobs that are posted on the

jobs board page hosted by Zero knowledge so check it out if you're looking for a job or if you just you know want to check out what's happening in the space yes if you're begging for some milk for instance and thanks to the team who put all of that together so Anna Kobe Agy hexo Rachel and myself