Bitcoin Forum

chain2 is an experimental cryptocurrency.  The main purpose of chain2 is to explore the performance of its difficulty adjustment algorithm: Real-Time Targeting (RTT). As a pure SHA256 PoW altcoin, chain2 competes for a share of the biggest pool of hashrate on Earth.

Miners and nodes wanted. This might be fun.


Download
https://github.com/chain2/chain2/releases


chain2 Mining - IMPORTANT

The RTT target starts low (difficulty high) and increases (decreases) during the block, depending the timestamp of the block being mined.  The next block's resulting nominal target is also included in the block template. It also rises with time, but is not the same as the actual target (see research paper).  Unmodified miners that rely on the template difficulty will fail to submit some valid blocks.

Slight (and hacky) modifications to pool software allow it to mine chain2 in a reasonable way, with no stratum client modifications needed:
 - ckpool https://bitbucket.org/dgenr8/ckpool/commits/26bfbcf5dd02f81094f92cbdda21802c3e132a64
 - yiimp https://github.com/dgenr8/yiimp-1/commits/next

The incentives established by this algorithm do not favor inaccurate timestamps, therefore using the timestamp as a nonce is not recommended.

chain2 lends itself to optimized mining pools and clients which understand RTT.  Please work on this if you can! An internal CPU miner is included for reference, but of course it is unusably slow.

Pools
https://mcpool.chain2.org/           -a sha256 -o stratum+tcp://stratum.mcpool.chain2.org:3330 -u -p c=CTWO

chain2 Specifications

- PoW algorithm: SHA256D
- Difficulty adjustment algorithm: RTT
   RTT research paper: https://github.com/chain2/chain2/blob/master/specifications/rtt.pdf
   RTT implementation: https://github.com/chain2/chain2/pull/6
- Starting difficulty: 1
- Starting target: 0x1d00ffff
- Block time: 10 minutes
- Block reward: 50 ctwo
- Block reward halving schedule: every 210,000 blocks
- Total coin supply: 21M
- Default P2P port: 9393
- Default RPC port: 9392
- Address format: cashaddr with "ctwo:" prefix (legacy bitcoin mode available)

- Pre-mine: No
- Founders reward: No
- Instamine: Not possible
- ICO: No
- Masternodes: No
- Segwit: No
- Finalization: No
- Genesis coinbase output script: OP_FALSE


BEWARE
If you somehow manage to buy ctwo from someone right now, you are extremely likely to lose money.  Chaotic reorganizations are quite possible. ctwo should never be worth anything unless it gains a meaningful level of stable miner support compared to BTC.


chain2 Consensus Rules:

    Bitcoin Cash rules as of 14 November, 2018 (PRE-SPLIT)
      (BIP143, 32MB blocks, etc ...)
    + Real Time Targeting
    + CHECKDATASIG activates at 75% support over 90 days (BIP135)
           * Activated 2020-07-29 12:14:35
    + Gradual max block size adjustment by miners (BIP100)


Reference implementation source code: https://github.com/chain2/chain2

Markets:
 - https://freiexchange.com/market/CTWO/BTC

Resources:
 - Explorer http://explorer.chain2.org
 - Explorer http://iquidus.chain2.org
 - Faucet http://faucet.chain2.org
 - Chat https://discord.gg/pydVnNh

Many BTC, BCH, and BSV applications are compatible with chain2 or could be made compatible with slight modifications.
Additional compatible implementations of chain2 are of course possible. PR's are also welcome to the chain2 reference implementation.


Consumer/Investor Disclosures

 - Cryptocurrency is a rapidly evolving technology.
 - Cryptocurrency has historically been EXTREMELY VOLATILE.
 - Transfers of ctwo are NON-REVERSIBLE.
 - Mined or transferred ctwo tokens may disappear in chain reorganizations.
 - The chain2 software is provided AS IS, WITHOUT GUARANTEE or WARRANTY.

How the chain looks so far

block, inter-block time, difficulty, target
0,1570992534,1,1d00ffff
1,9746,1,1d00ffff
2,240,183.9942093834309,1c01642e
3,661,77.56481858194326,1c034ce8
4,500,174.547270514061,1c017775
5,540,247.5244544770504,1c0108c3

Two successive GBT's have different targets and nbits. Target increases until a block is found. nbits won't be used until the next block and depends on this block's timestamp:


getblocktemplate

{
...
"previousblockhash": "0000000000093658813abd9f0c97b05cb5e3d23594b17c8abf27919312158af3",
"target": "0000000000b4d61573b036be175f295d6cd1e1d9c839e58cc85db34cd0760100",
"mintime": 1571004547,
"curtime": 1571005288,
"bits": "1b2a1d9c",
"height": 7
...
}



getblocktemplate

{
...
"previousblockhash": "0000000000093658813abd9f0c97b05cb5e3d23594b17c8abf27919312158af3",
"target": "000000000124ab302ef78bfb86628340481f85b4f0e6808b8ef587995ef7ced8",
"mintime": 1571004547,
"curtime": 1571005363,
"bits": "1b4b0ce2",
"height": 7
}

No website yet? Purchasing a domain is very cheap now. At least have official website for this project where everyone can check out with. No premine, no ico, no masternode, is a good start but creating value for your coin is not an easy task.

Hey Twinkledoe thanks!  Lets see if it can survive. For a SHA256 coin that would be valuable :)

hi

How can we avoid the problem with the prefix on wallet address, therefore we cannot mine it.


I've tried the pubkey generated with the prefix ctwo:address

ctwo:qr8ewlqzf85v0szmxtmfypunsmrtq9nm2gct7tdk8n



, it starts with c :   cf977c0249e8c7c05b32f692079386c6b0167b52



Also cannot create a legacy wallet address as you mentioned that it was possible. I've tried with the command :  

getnewaddress "nameofaccount"  "legacy" 



Is there another way ?


Thanks

The simplest thing is to restart chain2 with -usecashaddr=0.

Functions to accept multiple formats or translate between formats could be added to the RPC.

Sometimes I've used this python-bitcoinlib script to get a legacy address from a pubkey (you can get the pubkey from chain2 using validateaddress):

python pubkey-to-mainnet-address.py <pubkey>

#!/usr/bin/env python
import sys
import bitcoin
from bitcoin.core import Hash160, x, lx
from bitcoin.wallet import CBitcoinAddress
def main():
    bitcoin.SelectParams('mainnet')
    print(CBitcoinAddress.from_bytes(Hash160(x(sys.argv[1])),0))
if __name__ == '__main__':
    main()

It worked ty !

---

RTT difficulty ajustment make it really difficult to mine, its very interesting  :)

Looks easy for you, getting all the blocks now  ;)

Difficulty up to the millions, block 26, average blocktime 555 seconds!

Oh sorry for all blocks xp !

Yes for difficulty it even went to 9 trillion for a moment lol

Hey. Tell me I wanted to include Your coin in my calculator https://calcminer.info/ but I didn't find the coin Explorer. Does it exist?

No explorer yet.  It would be great if someone wanted to put one up!

I'll make one when ill be back home :)

EDIT: It's compiling & will be ready soon

---

I'm just gonna need a logo of the coin, do you have one ?

Thanks MCP!!

Lol no, graphics and front-end are NOT a strength of mine. If you don't feel like pushing pixels either, I'd say just go minimalist (text) for now!

http://45.63.9.40/ explorer  :)

---

If anyone wants to mine it , i installed it on this pool but it might be temporary because its a small pool with low RAM we should get it on another one if we have a lot of miners, i think it can runs max 50 miners something like that , not sure :



https://gnark-mining.com

-a sha256 -o stratum+tcp://gnark-mining.com:3338 -u -p c=CTWO

New to mining. Is there a wallet ?

Hi Daddygogo, are you looking for binaries? Working on that. Feel free to join us at https://discord.gg/pydVnNh

I believe he was asking for a qt wallet or daemon, already compiled and ready for use

Official binaries are now posted here:

https://github.com/chain2/chain2/releases/tag/v0.11L


The signature in SHA256SUMS.asc is with the same key I used to authenticate all Bitcoin XT releases since 2016,  fingerprint = 8F6E DE3A 88F8 6BC6 F982  55D7 F5D9 9379 1A77 8012

What's the point of a chain that reorgs ad infinitum? It's an interesting idea, but practically not really useful.

Yeah, I guess I have to solve that problem too.  Do I have to do everything myself?  ;D

Someday it might have a majority. So maybe you should mine some now, just in case.

If there is a reorg, just mine on top of it and be glad you didn't waste any resources you couldn't afford to lose, or accept ctwo in exchange for anything of value.

new pool:

https://miningcoins.ca

Somebody 's mining on https://miningcoins.ca with the wrong wallet address format   with prefix " CTWO: "

Please start you wallet-qt with the command  " -usecashaddr=0 "

It will give you a wallet address with the format like   " 1CGFu8RuKSob3tRvyXVdhDsG2wPJ4vM82j "

The pool cannot payout if you don't do this  

How to get your wallet giving you a legacy wallet to be able to mine on pool :

Download video:
https://miningcoins.ca/Chain2_legacy_wallet.mp4


On YouTube :
https://youtu.be/cpbiYHMe8Ng

The research paper has been updated.  The constant in section 3.3 is now derived rather than just referencing simulation results. Also various other clarifications.

https://github.com/chain2/chain2/blob/master/specifications/rtt.pdf

New pool!

Chain2 is added to pool.gpuhot.com (https://pool.gpuhot.com) mining pool.

Legacy address only  :-\



https://cdn.discordapp.com/attachments/450006856958607367/639135348135428126/unknown.png

Faucet currently offering 1 CTWO

http://faucet.chain2.org/

Actually Tom,
First of all thank you for posting this,  I was thinking about intra block retarget last 4-5 months then I found your implementation.  My point was: if you want blockchain with 10mins block spacing, why you would like to hash and use x KW to do it between blocks?  I appreciate your white paper(bloody hell much more than I appreciate it).  I would like to see some stress test.
nyo_x

What do you mean? Can you clarify?

New explorer live at http://explorer.chain2.org/

Sorry I was just thinking loud. For example: you want POW(no POS, Masternodes...) blockchain with 10min block spacing. This is done so far by looking back to previous x blocks solved at time y, and calculated next block diff(depends on implementation). You made first step in diff retarget intra block. But why to waste electricity between blocks. you can set the diff between blocks to diff, which is way higher than current diff of BTC and after 10min or 9,(xx/sec/)(which is your target) you can drop it to lets say "gpu solvable levels", so the block will be lottery. Doesn't matter if you have 100PH or 100GH. Of course everyone will be mining other coins between your blocks. But you will have still same blocktime and emission of coins like before. Next thing is economy, all the pow coins are valued by electricity spent on mining(so basically if you didn't waste a lot of electricity minnig some POW coin its not valuable). In my opinion, I rather prefer to mine some lottery block, if I'm not whale or don't have enough money to invest into some ICO, IEO..., or I cant mine high hashrate project. Imagine mining every 10 min xy miners with GPU's.

Ok so you did mean kilowatts (KW).  Yes, you've got it.

yes, sorry