Block Header

Block Header

General format of a Block Header in a MilbleWimble/Grin block:

Field	Description	Size
version	Version of the block	2 bytes
-	-	-
height	Height of this block since the genesis block (height 0)	8 bytes
timestamp	Timestamp at which the block was built	8 bytes
total_difficulty	Total accumulated difficulty since genesis block	8 bytes
output_mmr_size	Total size of the output MMR after applying this block.	8 bytes
kernel_mmr_size	Total size of the kernel MMR after applying this block.	8 bytes
nonce	Nonce increment used to mine this block.	8 bytes
scaling_difficulty	Difficulty scaling factor between the different proofs of work.	8 bytes
-	-	-
previous	Hash of the block previous to this in the chain	32 bytes
output_root	Merkle root of all the commitments in the TxHashSet	32 bytes
range_proof_root	Merkle root of all range proofs in the TxHashSet	32 bytes
kernel_root	Merkle root of all transaction kernels in the TxHashSet	32 bytes
total_kernel_offset	Total accumulated sum of kernel offsets since genesis block.	32 bytes
total_kernel_sum	Total accumulated sum of kernel commitments since genesis block.	33 bytes
-	-	-
pow	Proof of work data	in case cuckoo 30: 154 bytes. cuckoo_size: 1byte cuckoo_solution: 42*29bits=153bytes
		Total: 405 bytes

Example

Here is a principle example of a MimbleWimle/Grin block header. The related block is included in Testnet3: 101888.

{
  "header": {
    "hash": "05d13a2c577d61aa14dbfec7c45d9e29f6d11061cad1d661f5c87ca01c54e3ff",
    "version": 2,
    "height": 101888,
    "previous": "00b71c2d61396cc8c8d4ceab5873fe02fce6ae04551215587965ba886da1237e",
    "timestamp": "2018-09-19T08:01:05+00:00",
    "output_root": "8ff517ead8629c976efa1e563837a8bf22350ff34814e6a6fb1b4fca566c8328",
    "range_proof_root": "dc7b23682174cae34b02133a3dd75aa7e59569f1ebb70ee83cf062ffa47cc25f",
    "kernel_root": "10e35fe2c53b6f02f897d96590018c94ae1d725f6f2379ea2f98f48e815075c9",
    "nonce": 5433731719227262135,
    "cuckoo_size": 30,
    "cuckoo_solution": [
      3529900,
      20756386,
      26687989,
      39915563,
      58664656,
      61742168,
      63254288,
      71098734,
      83570003,
      92674712,
      99388329,
      150235082,
      159108923,
      186105999,
      188490539,
      191860971,
      197357411,
      223582317,
      226904112,
      240419493,
      243932605,
      305146957,
      322564448,
      358066753,
      363881523,
      365986157,
      368466480,
      386129065,
      403519432,
      415295811,
      430013252,
      452008276,
      456646007,
      469313754,
      470927182,
      472356191,
      476693937,
      489734253,
      501080796,
      501333167,
      502672154,
      533114222
    ],
    "total_difficulty": 45101558,
    "total_kernel_offset": "2c76d088abae094dcdd858a492d2ee57e107727db63889f342eeb4ea7ad1aef2"
  },
}

Description

TODO