NXT cross chain transaction 3M to 5M bounty

[ChuckOne]

Is this relevant at all to the discussion?

CoinWitness: https://bitcointalk.org/index.php?topic=277389.0

That is really interesting, especially for AT: https://bitcointalk.org/index.php?topic=463731.0
I sent CIYAM Open a PM on that. Thank you very much for that.

For CCT, as it builds upon AT and AE, we need should not need to bother with that as the 'dirty' work is done a layer underneath of us.

[swartzfeger]

Is this relevant at all to the discussion?

CoinWitness: https://bitcointalk.org/index.php?topic=277389.0

That is really interesting, especially for AT: https://bitcointalk.org/index.php?topic=463731.0
I sent CIYAM Open a PM on that. Thank you very much for that.

For CCT, as it builds upon AT and AE, we need should not need to bother with that as the 'dirty' work is done a layer underneath of us.

Chuck, there are two more posts similar to that one that I think are also relevant -- I am hunting them down.

I'm glad you forwarded that to CIYAM, because that's definitely beyond my pay grade.

[annable]

any other detail??

[ChuckOne]

We also need to discuss how automatic we want to have CCT.

If we want everything (including creating BTC transactions), we somehow need to create them without the users direct intervention. Storing some private keys in the NXT blockchain is not an option.

[msin]

We also need to discuss how automatic we want to have CCT.

If we want everything (including creating BTC transactions), we somehow need to create them without the users direct intervention. Storing some private keys in the NXT blockchain is not an option.

Yes, agreed,  I would say make it fully automatic

[ChuckOne]

We also need to discuss how automatic we want to have CCT.

If we want everything (including creating BTC transactions), we somehow need to create them without the users direct intervention. Storing some private keys in the NXT blockchain is not an option.

Yes, agreed,  I would say make it fully automatic

That would be the most convenient option, I know. But how to create a blank transaction without the private key of the user AND without revealing the secret necessary to perform the corresponding transaction on the other blockchain.

We have time to discuss this until AT and AE are up and running.

[jl777]

https://github.com/Coinffeine/coinffeine/wiki/Exchange-algorithm

Highly relevant

[msin]

We also need to discuss how automatic we want to have CCT.

If we want everything (including creating BTC transactions), we somehow need to create them without the users direct intervention. Storing some private keys in the NXT blockchain is not an option.

Yes, agreed,  I would say make it fully automatic

That would be the most convenient option, I know. But how to create a blank transaction without the private key of the user AND without revealing the secret necessary to perform the corresponding transaction on the other blockchain.

We have time to discuss this until AT and AE are up and running.

Yeah, that's the 3Mil Nxt question right there.   

[CIYAM]

Is this relevant at all to the discussion?

CoinWitness: https://bitcointalk.org/index.php?topic=277389.0

That is really interesting, especially for AT: https://bitcointalk.org/index.php?topic=463731.0
I sent CIYAM Open a PM on that. Thank you very much for that.

Unfortunately the CoinWitness thing and SCIP "goes right over my head" so I won't be specifying anything like it with our initial AT.

For the case of atomic cross-chain transactions an AT to do the equivalent of the pair of Bitcoin txs required is actually quite straight forward.

It will require a specific Nxt AT API command to "verify that the SHA256" of a value matches what is expected (this will need to be discussed with CfB).

Anyway after you've signed and returned the Bitcoin refund to the person wanting to buy NXT from you then you publish an AT containing the SHA256 hash the buyer sent you and their account # (for sending to if it proceeds) and giving that AT the agreed amount (so the NXT is under the AT's control).

The guy wanting to purchase NXT then sends the "secret key" as an AM to the AT - the AT will verify that the secret in the message is correct (i.e. when hashed gives the matching value) and then sends its balance to the "NXT buyer".

The NXT seller would then have to fix up the raw transaction by inserting the secret into it and broadcasting it (not quite as easy actually compared to the Nxt side of things) although it should be easy enough to "whip up" a script or small program to help with the Bitcoin side of things.

[msin]

We also need to discuss how automatic we want to have CCT.

If we want everything (including creating BTC transactions), we somehow need to create them without the users direct intervention. Storing some private keys in the NXT blockchain is not an option.

Yes, agreed,  I would say make it fully automatic

That would be the most convenient option, I know. But how to create a blank transaction without the private key of the user AND without revealing the secret necessary to perform the corresponding transaction on the other blockchain.

We have time to discuss this until AT and AE are up and running.

Any progress on this?

[msin]

This is from ChuckOne regarding his work on Cross Chain Transactions (CCT), we need input to help develop:

I am waiting for:
 - AE and AT
 - usability/security ideas/suggestions in the CCT thread, i.e. in which want you as a user trade BTC and NXT?

As you might imagine it's not just "click a button and let NXT trade BTC <-> NXT". You need to somehow specify your BTC account, your NXT account. So, do you want to store you bitcoin-wallet in your CCT/NXT client? How much convenience do you as user need/want?

What are the restrictions? Do you want to be online when the transactions are exchanged (remember: we cannot store private data on the blockchain)? How long do you want to be online? Do you have client/node you trust that can be online for you for the time being to refund in case your trading partner scammed you?

[mczarnek]

Think I figured this one out, it requires that a few forgers all agreeing whether or not a transaction has gone through though, a couple of them can play dirty and it still works.

Already sent it to some of you but anyone who wants to see my algorithm, shoot me a PM and I'll send it to you.  I am a programmer but haven't touched Nxt source code yet and would most likely need help implementing it!

[jabo38]

5 million nxt!  isn't that like $25,000,000?  for the person or team that figures this out, it is enough to retire for life!

[cryptohunter]

5 million nxt!  isn't that like $25,000,000?  for the person or team that figures this out, it is enough to retire for life!

no. nxt is still just a few cents each.

[mczarnek]

5 million nxt!  isn't that like $25,000,000?  for the person or team that figures this out, it is enough to retire for life!

no. nxt is still just a few cents each.

You mean it's a few cents each until someone figures out this problem?

As far as I'm concerned, each nxt is worth about $10

[jabo38]

5 million nxt!  isn't that like $25,000,000?  for the person or team that figures this out, it is enough to retire for life!

no. nxt is still just a few cents each.

ahhhh, right $250,000.  Still..... that is quite a nice bonus!  I am guessing somebody will get this done. 

[mczarnek]

The problem is, it hasn't been known whether or not a trustless solution exists.

I've got an idea for one that at least requires multiple trusted accounts ganging up to mess things up.. which may be too much trust.  PM me to find out more if you can help me implement it. Thanks.

[allwelder]

anyone worked on this project?

[msin]

anyone worked on this project?

AT needs to be completed.

[HumanFractal]

Is this bounty still active?

Who put up the 3-5M? Was it you pinarello?

I would give this my best shot, and find some others with cryptographic / programming experience to see if this can be done.