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Shuffling Sunday !

Come and test out the 1.7.2e CoinShuffle feature this Sunday, 13-12-2015



Ladies and gentlemen: the core devs have asked me to organise some serious testing (on TestNet) for the CoinShuffle feature in NRS 1.7.2e.

The target is to get as many participants into shuffles as possible, and to generally stress test and bug hunt in 1.7.2e.

What else do you have to do on a Sunday, eh ?



What you will need to do:



Set up a TestNet node using NRS 1.7.2e



Set up a TestNet account, and get some TestNXT on the account (ask me, I'll be getting a fat stack tomorrow)



Start your TestNet node up early on Sunday, and at 16.00 UTC, log in to your accounts and get shuffling.



Leave your nodes running for as long as possible, preferably 24 hours at least.



Report your experiences with the shuffle system.



What you will get :



The devs will give you some love, CoinShuffle will get some serious testing that we can document and use for PR. We may even find some problems and get them fixed before CoinShuffle goes live.....and the NXT Foundation/TNSSE will provide a very slightly generous bounty pot to be divided among the CoinShuffle testers.



I'll post more details later on during Friday, including technical info for those who have never used TestNet before, how to use CoinShuffle, and the exact size of the bounty pot. In the meantime, spread the word......





Shuffling Sunday II: Sabotage !

Quote from: EvilDave on January 07, 2016, 02:02:13 pm Nxt core devs: Jean-Luc and Riker, would like to invite everyone to attempt to break/damage/compromise Shuffling in whatever evil ways they can think of......

Note that shuffling sabotage exploits should be economically rational, i.e. cheaper to perform than the 1000 NXT it costs to break a shuffling by just missing your turn. I am already aware of one possible way to break a shuffling and blame it on someone else, but it is too computationally expensive to be practical.



Few more things, we are quite sure that if you work using the wallet UI you won't be able to break anything, however even if you are not a coder it would help a lot if you try the system as a user if only to generate good test data and provide feedback about the user interface.

It would be great if you can run your own testnet node. Feel free to shuffle using more than one account and more than one node at the same time. You can even try with the same account on different nodes, the blockchain should be able to handle these cases.

If you need testnxt post here.



We suspect that to really break things you'll need to review the source code and submit transactions manually (i.e. not rely on the default shuffler, perhaps try to create an evil shuffler)

To start with, checkout the 1.7.4 source code available here https://bitbucket.org/JeanLucPicard/nxt/src , I recommend that you focus on the Shuffling*.java and Shuffler.java sources under the java/nxt folder. One thing we sometimes get wrong is the validateAttachment methods in ShufflingTransaction.java, if you find something there that's a low hanging fruit.

The main algorithm is implemented in the Shuffling.process() method and the source code for blaming a cheater is in the blame() method.

In my view, if you are able to break things really badly and explain what you did we can probably provide a larger bounty.



It's time for the sequel:From the previoustests, we are pretty sure that all of the CoinShuffle technology works well in 'normal' use.But what about abnormal use ?Nxt core devs: Jean-Luc and Riker, would like to invite everyone to attempt to break/damage/compromise Shuffling in whatever evil ways they can think of......So, on the 2 following Sundays (that's 10 and 17 January 2016), from 12.00 UTC onwards, everyone is invited to test/break Shuffling functionality on TestNet.All of the details on how to get onto TestNet are at the start of this thread:Please note that we will be testing withonThe Nxt Foundation/Tennessee will provide some bounty payments: we will pay out a small bounty amount to testers for participating, as we did with the last Shuffling Sundayprovide a single bounty payment of 25,000 NXT for finding a bug/exploit in the Nxt CoinShuffling implementation.(I'll award the participation bounty, the bug bounty will be decided by J-L and Riker, if anyone finds an exploit)See you on Sunday...., spread the word.