Dash is a general purpose cryptocurrency featuring quick and low cost transactions, privacy functionality, active community support, and decentralized project governance. Developed by Evan Duffield, Dash introduced several novel blockchain technologies, including a unique hashing algorithm that resists ASIC mining, and influenced projects through their pioneering work in governance design. Dash practices ‘Decentralized Governance By Blockchain’, with the community and masternodes discussing and deciding upon which project development proposals to fund through an internal treasury that draws from block rewards. Dash’s efforts to promote cryptocurrency adoption have seen success in Venezuela, where Dash has seen use. Dash’s token, DASH, is a medium for exchange and store of value, and can confer voting rights with respects to project governance.
Dash uses a combination of Proof of Work (PoW) and Proof of Service for consensus, with mining and masternodes providing two layers of security. PoW mining in Dash employs a proprietary X11 mining algorithm to prevent double spending and secure transactions. X11 uses a sequence of eleven unique hashing algorithms that require sequential, repeated hashing. This design makes engineering an ASIC that can outperform CPU and GPU miners more difficult, as ASICs are generally designed to efficiently solve a single hashing algorithm. Masternodes provide additional oversight through their powers to reject improperly formed blocks, monitor that miners use current preferred software, and orphan blocks. Masternodes run separate from mining and a user must hold 1000 Dash in collateral to operate a node.
Masternodes additionally perform Dash’s Instant and PrivateSend services, and participate in project governance through voting on fund allocation proposals through Dash’s treasury DAO. Masternodes are selected pseudo-randomly each block to perform Instant-and-PrivateSend services, and masternodes behavior is monitored using ‘proof-of-service,’ which temporarily bans a MasterNode from the network if they do not perform their functions during that block.
InstantSend functionality allows masternodes to confirm transactions within a few seconds. These transactions are designated with a special command in the code and sent to a set of ten MasterNodes that are selected pseudo-randomly each block. All ten need to agree on the transaction, then broadcast it to the network and lock the funds. Thereafter, if any sender other than the recipient attempts another transaction with those funds, all nodes reject it. This enables funds to be spent multiple times in one block.
PrivateSend is an optional mixing protocol that allows users to make pseudonymous Dash transactions. Mixing allows transactions in Dash to be pooled together with other transactions of similar size, then potentially remixed with other pools, making it difficult to track individual transactions. This takes significantly more time than a transparent transaction and users must designate which transactions they want to go through a PrivateSend mixing process.
Dash’s ‘Decentralized Governance by Blockchain’ (DGBB) process allows masternode operators to approve project initiative and software upgrade proposals via treasury allocations. The process is designed to make Dash more independent and self-sustaining compared to projects relying on non-profit foundations for governance; the project does not depend on grants, donations, or corporate sponsors as sources of income for project development, instead relying on a treasury funded through 10% of the currency’s block rewards.
Dash’s token, DASH, functions as a general purpose cryptocurrency. Those willing to hold 1000 DASH in collateral can participate as a masternode, earning a portion of block rewards for security, instant and private send services, and conferring voting rights over project governance.
Of each block mined, 45% is allocated to masternodes, 45% to miners, and 10% to Dash’s treasury. The block reward, 5 DASH at genesis, is designed to fall by approximately 7% every year, but several features of Dash's monetary policy make the future supply unpredictable. First, the block reward increases as the difficulty increases, incentivizing mining if it falls. Second, any unused treasury funds are effectively burned (technically never minted if there aren't approved budget proposals to accept them). Third, budget proposals result in 5 burned DASH. This results in a range estimate on DASH's eventual supply of 17.7m to 18.9m DASH.
DASH did not have an initial 'premine' distribution or token sale, but it did have an 'instamine' period in which approximately 2m DASH were distributed in the first 48 hours. The instamine is a result of the algorithm that adjusts block rewards based on difficulty; the initial period of the network, with a low difficulty, resulted in high initial inflation.
The PoW component of DASH’s consensus process uses a unique hash algorithm, X11, developed by DASH founder Evan Duffield in 2014. It consists of 11 sequences calculations in which the output of the previous hash is an input to the next; the algorithm at each stage is unique. The hope was that by requiring memory to store the intermediate outputs and using 11 different algorithms, X11 would be less susceptible to ASIC development, though Duffield has stated he intended X11 to follow a similar migratory path from CPU to GPU to ASICs mining seen in Bitcoin. The use of 11 algorithms was also intended to make X11 more resilient to any exploits found in any single algorithm. CPU and GPU mining, possible in the early days of DASH, have been replaced by increasingly sophisticated ASIC mining equipment. As the crypto industry has learned, even memory-intensive hash algorithms are susceptible to ASIC development. In late 2016, the first mainstream ASICs were released. As of late 2019, there are a handful of competitive ASIC manufacturers, ranging from Bitmain’s Antminer D3 to high-cost Spondoolies; there are a variety of mining pools, but the vast majority of hash power is concentrated in three China-based mining pools.