DGW or Dark Gravity Wave is an open source difficulty-adjusting algorithm for Bitcoin-based cryptocurrencies that was first used in Darkcoin and has been adopted by other digital currencies.
DGW was authored by Evan Duffield, the developer and creator of Darkcoin, as a response to a time-warp exploit found in Kimoto’s Gravity Well.
In concept, DGW is similar to Kimoto Gravity Well, adjusting the difficulty levels every block (instead of every hundreds of thousands of blocks like Bitcoin) by using statistical data of the last blocks found. In this way block issuing times can remain consistent, despite high fluctuations in hashpower. However it doesn’t suffer from the time-warp exploit.
Version 2.0 of DGW was implemented in Darkcoin from block 45.000 onwards in order to completely alleviate the time-warp exploit.
Version 3.0 was implemented on May 14 of 2014 to further improve difficulty re-targeting with smoother transitions. It also fixes issues with various architectures that had different levels of floating-point accuracy through the use of integers.
Several alt-coins have adopted DGW in order to prevent the time-warp KGW exploit.
- Electronic LIRA
Note: The above list is not updated anymore due to the large number of new coins implementing DGW