Topic: [ANN] Zcoin (XZC) - Implementing ZKP privacy without trusted setup - page 170. (Read 663229 times)

Thanks. Oh and I submitted a 2nd attack, this time a flaw in the MTP algorithm itself. https://twitter.com/zorinaq/status/889990807519870979

Hi all. I like your project. Specially interested about MTP algo.
Please add support DDRX5 memory and all 1080ti owners be happy too

Submission is accepted! Thanks for this! Keep them coming! The bounty is divided between each bug found so the more you find the bigger the share of the bounty you get!

The bug happened when increasing the number of blocks required without adjusting this parameter. Good spot!

Took a break on Sunday but am asking the devs to look at it. Need much more details tho. Only reason I brought it to PM was cause we probably need some private details from you like your wallet.dat. Still trying to process everything you wrote to communicate it with the devs.

Both start with a ''Z'' 

how about you go to youtube and type in: ''zcoin vs zcash''... you will find all your answers in Reuben's interviews

how does this coin compare to zclassic?

in anyone cares for an update, I did get back the 50 xzc from the second mint zero coin transaction but the first transaction is still gone. Waiting for some sort of helpful advice, have not received any yet. The second 50 zerocoin minting went smoothly without a hitch but the GUI did not liberate the coins, it presented an error message. When I 'spendmintzerocoin' from the console it worked fine. Still puzzled why the GUI would present an error message for the same function that works when called from the console. no explanation here.

In my opinion it is imperative/critical for the mint zero coins to NOT DISAPPEAR. I see everyone talking about pressing on with miner dev bounties and new MTP but the basic foundation of zcoin has malfunctioned and there seems to be very little regard to this issue. I have plenty of zcoin and only wish to see them gain value. I seriously doubt there is a future if this problem is not addressed. And why it has been postponed without public response is troubling me.

Great Job!! Keep it coming let's perfect this thing and rocket Zcoin to the stars!!

I submitted a first—critically exploitable—bug last night. SHA256 of the description of the bug at https://twitter.com/zorinaq/status/888644581926944768 Thank you for organizing this!

Well it's not a Zcash fork but an independent development – it actually launched before Zcash.

Zcash (& all its forks) has the problem of lacking supply auditability, meaning if any malicious person ever finds a bug that allows for double spends or anything like that, they could create an infinite amount of currency without it being detectable. Zcoin doesn't have that problem because it shows transaction amounts, even in zerocoin spends (Zcoin's equivalent to shielded transactions, roughly speaking).

Also this year or next year the trusted setup, which is still at the core of every zerocoin/zerocash-based cryptocurrency, will be ditched in favor of the trustless Sigma protocol in Zcoin.

It wasn't botnets as far as I know, a bunch of people just found out how to get AWS credits for free and unleashed insane numbers of Amazon instances on Zcoin.



It's been Lyra2Z since February... MTP is running on testnet and open source miners are being developed, and at the moment it's scheduled to launch at block 47500 (which should be around August 13), barring any further delays due to weaknesses found or anything like that.

How this coin compare to Hush?

ah oke I think I missed this bc I dont follow tread enough. I thought we where allready on MTP algo but where on lyra2z now instead?

I know botnets where there form the start we had a different algo then but I thought the new algo was supposed to fix this, or at least make it a lot less feasablie to do. asics seemed like not a option to me thats why I said it seemed highly unlikely, thats why I was wondering how the high hashrate could be explained.

haha dude do you think it's possible to do "aws cloud mining" with hash power 65K GPU (not cpu core, which is  if translate to cpu maybe around  195K  ?? )?? yes it might be if using legal ways , but their outcome will more bigger than their profit a.k.a more cheap to buy zcoin than to mining using  cloud mining

Will pm you! Are you on Slack?

attn zerocoin team:

I am in the midst of testing zcoin rpc software and zcoin-qt wallet on ubuntu 16. this communication postponed for 24 hours until I was (mostly) sure there is some sort of problem.

PLEASE HELP:

I have 100 XZC in limbo right now, a result of testing the zerocoin function. there were two portions of 50 and stupidly enough I committed to the second portion before the first was finished. Hopefully this folly can help with development and to be honest it is difficult not to be extremely upset about this. I know this is 'experimental software' but those coins will be worth most likely over $100K in just a few years. So why don't we attempt to fix this?

Here is the sequence of the problem. The goal was to'zero' two 50x portions of coins for a total of 100 coins and send each portion to a new wallet in another user account.

transfer 1:
-----------
Status: 0/unconfirmed
Date: 7/20/17 16:45
Source: Generated
Credit: 50.00 XZC
Net amount: +50.00 XZC
Transaction ID: b70404e9d07a13f1816e7ad723c31b04d810c998ff3d6571f737909ab25d7281
----------
These coins should have been confirmed by now after 24 hours right? Not sure how long it requires to verify zerocoin. I did mint the 50 coins just fine and when they were sent to my wallet the transaction basically disappeared from the network. In my dialouge it told me it had been broadcast to over 45 nodes but after over 16 hours I am giving up that they will confirm it. I restarted the wallet and the above "cut-paste" is from the wallet restart. Now is says it hasn't been broadcast at all (there is no "number of nodes who saw it" anymore). How do I fix this? The coins have been in limbo too long, thats too much damn money and it wasn't my mistake!!

SECOND MINTING OPERATION: I now have a minted 50 coin chunk in the "zerocoin" tab on the qt wallet. When I attempt to liberate this chunk into xzc tokens I received this message from the GUI and sometimes it alternates with another one:
---
You cannot spend zerocoin because it has to have at least two mint coins with at least 7 confirmation in order to spend a coin
---
Error message from debug console:

15:52:14
spendzerocoin 50
15:52:14
at least two mint coins are using calculating accumulator (code -4)
----


I did receive the first error message yesterday when the first 50 coins were minted (from the qt gui), note: I did a retry to send the same 50 coins just seconds later from the debug console. It claimed success and provided the above (top of message from first transfer) transaction ID. however, no coins were ever confirmed.

OF COURSE I AM CONCERNED ABOUT "-RESCAN" BECAUSE WHEN I DID THAT I LOST THE (1) XZC THAT WAS IN THE MINT (this is a separate transaction, the other day when I first tested xzc) WITH NO WAY TO RECOVER. RIGHT NOW THERE ARE FIFTY XZC IN THE MINT AND I AM CONCERNED THAT THEY WILL DISAPPEAR ALSO!

My blockchain is current. I have tried everything from the sparse information I have been able to glean from the web. I checked all the sites. Absurdly enough, when I searched for "You cannot spend zerocoin because it has to have at least two mint coins with at least 7 confirmation in order to spend a coin" in google I was shown the imposters "zoin" page here on bitcointalk and they mentioned this "bug" in ya'lls code.

I am a big fan and supporter of Zcoin I hope nobody gets the wrong impression! It is quite simple that 100 XZC is most of my savings (yes I put my savings in experimental software, jeez) .. Because I have a strong support for this project and I wish it to work.

------

If I am unclear about anything, let me know. I have all the data but the trans ID isn't showing up on the blockchain from the first spend mint zerocoin transaction. I don't know if backing up that code sequence that equates to the second 50 xzc that was burnt from my wallet would do any good. I saw no option to recover or restore from that code.

IF I AM MISSING SOMETHING (other than 100 XZC currently) I WOULD LOVE TO HEAR IT !

thank you for your time.

Do you guys seek German translation? Seek no further. Ich bin euer Mann! (I am your guy)

Bounty for MTP Audit ($10,000) and MTP Implementation ($2,500)



We are announcing bounties for MTP audit and MTP implementation.

MTP (Merkle Tree Proof) is a new proof of work algorithm that was presented at the USENIX Security Symposium 2016 and has attracted substantial attention from the cryptocurrency and academic community. To further encourage research and scrutiny into MTP, we are sponsoring two bounties.

MTP Audit Bounty: 10,000 USD Total
MTP Implementation Bounty : 2,500 USD TOTAL

Deadline of submission is 30 September 2017 but remember it is better to submit early as duplicates are not rewarded.

Further information about rules and bounty distribution can be found in our blog post:
https://zcoin.io/bounty-mtp-audit-10000-mtp-implementation-2500/

The Lyra2z algorithm was meant to make it much less profitable for botnets to mine Zcoin since GPUs were viable and had some advantage over CPU. I don't think it has a lot of memory though especially when compared to the original algorithm.
Blake256 first round and Lyra2 (timecost = 8, r=c=8). Remember this was a placeholder algorithm.

Given that this is a transition algorithm that is due to be phased out when MTP comes along, it is pretty unlikely that an ASIC has been developed and plus we're a new coin in a rapid state of change.

Previously we were made aware of a sizeable private Nvidia GPU farm that was mining Zcoin since the Lyra2z switch on their own private pool but we really don't know if it's them.

The last I tried mining Zcoin with my Nvidias, it was less profitable than other coins but not THAT much so to make it unthinkable.