Archives for SHA256
Genesis Block
Every cryptocurrency derived from Bitcoin has a Genesis Block, the very first block in the blockchain, whose creation is hard-coded into the full node code. In order to prove that it's authentic, the usual rules about hashing the Merkle root and the Consensus information apply. So, one has to come up with some seriously magic numbers to put in the code. The established technique, documented in all the coin cloning guides, involves setting the values to zero for the very first run, getting an error message and using the values displayed in the log file to fill into the source code. However, the section in the Bitcoin code that computes the required hashes for debug printing has been removed from…
Difficulty Re-Targeting
Adjusting (re-targeting) difficulty for the PoW is a complex issue with Cryptocurrencies. Bitcoin adjustment every 2016 10 minute blocks (two weeks), is very coarse, and is not usable for smaller coins, in the age of ASIC and GPU farm mining, where hashing on a particular network can change very rapidly, sometimes automated or performed for malicious reasons. A range of algorithms and techniques are evolving and many have been implemented and deployed since. Kimoto Gravity Well (KGW) Nite's Gravity Well Dark Gravity Wave Digishield from Dogecoin had time-warp vulnerabilities but was fixed-up in other coins since. Slingshield also made improvements of some sort. Zcash settled on adjustment for every block, after an extended discussion. They implemented a modified Digishield v3. Despite prolonged discussions, Litecoin…
Walletbuilders
A well-known Walletbuilders service will automatically make a coin for you, a free one that only includes Linux and Windows node executables, or for BTC they will let you create a custom one, with your own signage, block parameters, Scrypt PoW and PoS that takes over, after so many blocks, etc. Pre-mine is an option. A seed service for your coin is included on their site, and perhaps a month of hosting a node. Additional hosting is BTC / month. They deliver with the paid coin product pre-compiled Windows and Linux executables for both a node (daemon) and a Qt GUI client. A unique pair of ports that they assign, is used to distinguish your network. Included source code does produce the two…