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Overview
Snowblossom is a proof-of-work cryptocurrency launched in May 2018 with a small set of deliberate design choices: an IO-bound proof of work that resists specialised hardware, a UTXO commitment in every block header so light clients can verify what nodes tell them, multi-algorithm multisignature addresses that already include post-quantum signature schemes, and a sharded chain (the “Braid”) that can split under load. This site documents all of it - from the bytes in a block header to running a pool.
Block height
-
mainnet, live
Active snow field
- · -
next: - at difficulty -
Difficulty
-
≈ -
Block reward
-
halves every 210,240 blocks
Active shards
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of 32 possible leaf shards
What makes Snowblossom different
Stoat: IO-bound proof of work
Every hash attempt needs six dependent random 16-byte reads from a multi-gigabyte “snow field”. Hash rate is bounded by storage IOPS, not arithmetic, so ASICs and GPUs gain little. Nodes verify with merkle proofs and never need the field.
Snow fields that grow with the network
Twelve deterministic fields from 1 GiB (“cricket”) to 2 TiB (“avanc”). Each time the average difficulty rises by two bits, the next field activates - permanently - keeping the working set ahead of cheap memory.
Multi-algorithm multisig & post-quantum keys
An address is the hash of an M-of-N spec over any mix of ECDSA, RSA, DSA, DSTU 4145, SPHINCS+, Dilithium and Falcon keys. Public keys are only revealed when spending.
UTXO root in every header
The unspent output set lives in a hashed trie whose root is committed in each block. Wallets verify balances and proofs against it instead of trusting the node.
Sharding built into the protocol
Since version 2.0 the chain is a binary tree of shards that split deterministically when blocks fill up. Rewards per height stay constant and cross-shard transfers are committed by root hashes.
Simple on-chain governance
Miners signal for or against numbered proposals in the coinbase. Six SIPs have been adopted this way, including sharding and the post-quantum signatures.
Quick facts
| Ticker / unit | SNOW; 1 SNOW = 1,000,000 flakes (all protocol amounts are integer flakes) |
| Launch | 22 May 2018, no premine, no ICO. Block 0 had to contain the hash of Bitcoin block #523,850 so nobody could mine early. |
| Block time target | 10 minutes (600,000 ms), adjusted every block with an exponential moving average |
| Block reward | 50 SNOW at launch, halving every 210,240 blocks (≈ 4 years) → supply converges to ≈ 21,024,000 SNOW |
| Hash functions | Skein-256-256 for block/transaction hashes, Skein-256-128 for snow-field merkle trees, Skein-256-160 for addresses, SHA-256 inside the UTXO trie |
| Address format | snow: + 40 base-32 characters (Duck32, a bech32-like encoding with a 5-byte checksum) |
| Wire protocol | Protocol Buffers over gRPC, for both peer-to-peer and wallet/miner traffic. Optional TLS with node identities derived from Snowblossom keys. |
| Implementation | Java, built with Bazel. One repository contains node, wallet, miners, pool and explorer. github.com/snowblossomcoin/snowblossom |
| Current software version | 2.2.0 (master: 2.2.0-dev). Consensus-relevant changes: header v2 since block 211,600 (sharding), post-quantum signatures since block 358,700. |
How this documentation is organised
- Start here - practical pages: Quickstart, the list of programs, how configuration works and an FAQ.
- Protocol - what the software does and why: blocks & consensus, the proof of work and its snow fields, transactions, addresses & signatures, sharding, networking and the network parameters.
- Running software - operating a node, the wallet, mining, the JSON-RPC and gRPC APIs, the explorer and an integration guide.
- Reference - proposals, history, security, a glossary and links.
Everything here was written from the source code of the reference implementation; where the code and older documentation disagree, the code wins and the discrepancy is noted. File paths such as lib/src/PowUtil.java refer to the snowblossom repository. Live numbers on this page come from the explorer API.