• Community site: https://xdag.io
• The Main net was launched January 5, 2018 at 22:45 GMT

• Directed acyclic graph (DAG), not blockchain
• Block = transaction = address
• Original idea and implementation
• Mineable, no premine, no ICO
• Mining new money every 64 seconds

• How to get a wallet
• How to getting started
• How to find pools
• How to contribute

• Wiki
• Whitepaper 中文版
• Protocol 中文版
• License

Every block in DAG has up to 15 links to another blocks (inputs and outputs). Block B is referenced by another block A if we can reach B from A by following the links. Chain is a sequence of blocks each of which is referenced by the previous block. Chain is called distinct if every its block belongs to separate 64-seconds interval. Difficulty_of_block is 1/hash where hash is sha256(sha256(block)) regarded as little-endian number. Difficulty_of_chain is sum of difficulties of blocks. Main_chain is the distinct chain with maximum difficulty. Blocks in main chain are called main_blocks.

Daggers are mined in every main block. There are three periods of mining:

The maximum XDAG supply is approximately 1.446294144 billion.

Each dagger is equal to power(2,32) cheatoshino. Transaction is valid if it is referenced by a main block. Valid transactions are strictly ordered depending on main chain and links order. Double spending is prohibited because only first concurrent transaction (by this order) is applied.

The on-disk format will change in the future. Consider this the network protocol. Each block has a fixed size of 512 bytes. Block consists of 16 fields each of which has length 32 bytes. Field 0 is header, it consists of 4 quadwords:

• transport-layer header
• types of all 16 fields, 4 bits for one type
• timestamp of the block, in seconds from Unix era * 1024
• block fee in cheatoshi

Types of fields:

0. nonce
1. header
2. transaction input: 24 lower bytes of block hash and 8 bytes of input amount
3. transaction output, structure is the same as input
4. half of block signature; ECDSA number r or s; digest for signature is hash of (block concate public key)
5. half of output signature; only owner of this key can use this block as input
6. public key (x) with even y
7. public key with odd y
8. header of testnet
9. ... 15. are reserved for future usage.

The dnet network is used as transport layer. A new transport layer will come in the future.

Evgeniy ( XDAG: gKNRtSL1pUaTpzMuPMznKw49ILtP6qX3, BTC: 1Jonano4esJzZvqNtUY6NwfPme3EMpVs7n )
Frozen ( XDAG: +L5dzSh1QZv1We3wi8Of31M8eHwQJq4K )

• trueserve
• sgaragagghu
• Sofarlemineur
• Chen Zhen
• kbs1
• amwsffgu
• s2n-gribbly
• reymondtu
• sugaryen
• mojs78
• rubencm
• SantoMacias
• cnukaus
• mathsw
• ruben
• Dengfeng Liu
• BinaryOverflow
• Caleb Marshall
• NKU-Nikoni
• Elder Ryan
• hughchiu
• Mingege
• p2peer
• ZR

Full list of contributors including all contributors for XDAG sub-projects.