X11 is the name of a chained hashing algorithm, which is used for the ‘Proof of Work’ calculations which secure the network of some cryptocurrencies.
It is known as a chained algorithm because it uses 11 different algorithms which are chained together. These are: blake, bmw, groestl, jh, keccak, skein, luffa, cubehash, shavite, simd, and echo.
The first coin to use it was Darkcoin, which has since rebranded itself as ‘Dashcoin’.
History & Background
X11 was developed in order to overcome some significant drawbacks associated with previously used cryptocurrency mining algorithms such as SHA-256 (Bitcoin) or Scrypt (Litecoin, Dogecoin). The biggest of these drawbacks was the fact that electronics companies had developed specialist hardware, called ASICs, for mining coins which used the SHA-256 and Scrypt mining algorithms. This had the effect of making the networks more centralized – controlled by a small group of powerful miners, whereas the original vision for cryptocurrency was for ordinary users to be able to take part in securing the network and earning rewards through mining. Mining centralization reducing network security, reduces the number of people with a stake in running the netwok who naturally become its advocates, and may increase the likelihood of mined coins being instantly ‘dumped’ as businesses need to cover costs and take profits whereas individuals may not have to.
By designing the X11 algorithm to be well suited to use with general purposes CPU processors and commonly used GPU graphics cards, and by cycling through many different algorithms rather than using a single algorithm, it makes it difficult for manufacturers to develop ASICs for coins which use this algorithm. Although it is possible that ASICs will eventually be produced, X11 coins are expected to remain ASIC-resistant for at least the short and medium term future.
The use of 11 different algorithms also increases the security of coins using this method against brute force attacks. Brute force attacks against coins, such as Bitcoin, which use other algorithms are not currently possible, but may conceivably be possible at some point in the future.
Another additional benefit of this algorithm compared to SHA-256 and Scrypt is the fact that it is less intesive and therefore uses less electricity. Computers running other algorithms tend to run very hot and use up a lot of electricity. For example, a graphics card running the Scrypt algorithm will produce 30% more heat than the same card running X11 – and this excess heat reduces the lifespan of the hardware as well as reducing overall efficiency.
List of Popular X11 Coins