Glossary

Terms used throughout this documentation and in the source code, in alphabetical order.

Activated field

The minimum snow field a block may use, carried in each block summary; increments when the average difficulty reaches the next field's activation difficulty and never decreases.

AddressSpec

The definition behind an address: required_signers plus a list of (signature type, public key). Revealed as a claim when spending. More.

AddressSpecHash

The 20-byte Skein-256-160 hash of an AddressSpec - the address in binary form.

Arktika

Distributed miner that serves 1 GiB field chunks from layered sources (files, RAM, remote machines). More.

Block summary

Per-block state kept by a node: cumulative work, running averages, activated field, shard bookkeeping. Not part of the wire protocol.

Braid

The set of interlinked shard chains introduced in 2.0; “Snowblossom Braid” is the name of the sharding design. More.

Channels

A planned peer-to-peer content distribution system (“blockchain meets BitTorrent”) whose name registration uses Snowblossom outputs with ids claims. Experimental builds exist as ChannelIceLeaf.

Claim

An AddressSpec included in a transaction to prove that the spender knows the preimage of an input's address.

Coinbase

Transaction 0 of a block: creates the reward plus fees, carries block height, shard id, remarks and votes.

Coin control

Choosing exactly which unspent outputs a transaction spends. The CLI names outputs as txid:index (shortened ids accepted) via outputs and --input; --from restricts to addresses. More.

Coordinator

The shard on the left-most lineage of the shard tree (0, 1, 3, 7, …); defines the canonical ordering of cross-shard imports.

Cover set

For a shard: the shard ids whose outputs live in its UTXO - its inherit set plus all descendants.

Deck

A file of precomputed snow-field merkle nodes at every 1024^k-word level (.deck.a, .deck.b, .deck.c) used to build PoW proofs quickly.

Difficulty

256 − log₂(target); the expected number of hash attempts per block is 2^difficulty. Display only - the protocol works with the 256-bit target.

Duck32

The text encoding of addresses: label + base-32 (bech32 alphabet) of 20 data bytes and a 5-byte Skein checksum that includes the label.

FBO

“For benefit of”: an optional output field naming another address the output is held for. Indexed by nodes; no consensus meaning.

Flake

The smallest unit; 1,000,000 flakes = 1 SNOW.

Hashed trie

A radix trie whose nodes are stored under the hash of their content, making every state addressable by its root hash and updates copy-on-write. Used for the UTXO set and the node's indexes.

IceLeaf

The desktop GUI wallet (with optional embedded node).

Imported block

A block from another shard carried inside a block together with the outputs it exported to this shard.

Inherit set

For a shard: itself plus ancestors reached while the id is odd; the left child inherits what belonged to the parent.

Key mode

Wallet setting deciding what new addresses are made of: seed, standard, qhard, pqc1, pqc_lite.

memfield

Miner option to hold the snow field in the JVM heap.

Motion

A proposal number voted on in the coinbase (motions_approved / motions_rejected). See SIPs.

MrPlow

The PPLNS mining pool server.

Node address

A Snowblossom address with the node: label identifying a node's TLS or trust-network key.

PPLNS

Pay-per-last-N-shares: MrPlow splits each found block among the shares submitted in a window sized to the last ~5 blocks' worth of work.

Pay ratios

Address → weight map in a block-template request; the node splits the coinbase accordingly. How pools pay miners.

PoolMiner

The standard miner that works for a MrPlow pool.

PQC

Post-quantum cryptography: SPHINCS+, Dilithium and Falcon signature types added by SIP-6.

Preview

A compact block reference (height, previous hash, hash, shard) used for synchronisation between peers.

QHard

Key mode combining secp256k1, RSA-8192 and DSTU 4145 in a 3-of-3 address; the 2018 answer to quantum computers.

Regtest / spoon

Local test network with 1-second blocks and tiny fields.

Rumour list

A node's persisted list of peers learned from gossip and seeds.

Shackleton

The block explorer software.

Shard

One chain in the braid, identified by its position in a binary tree (children 2p+1, 2p+2).

Share

A PoW solution below a pool's easier per-miner target, proving work done.

SIP

Snowblossom Improvement Proposal.

Skein

The hash function family (SHA-3 finalist) used for blocks, transactions, addresses and snow-field merkle trees.

SNOW

The currency unit.

Snow field

A large deterministic pseudo-random file read during the proof of work; mainnet fields are named cricket … avanc, 1 GiB to 2 TiB.

Snow monster

The 256 MiB pool of generator history that SnowFall mixes back into its PRNG, making generation memory-hard.

Snow storm

The activation of the next snow field.

SnowFall / SnowMerkle

The programs that generate a field and compute its merkle root and decks.

Stoat

The name of the proof-of-work function (hashes hop around a snow field).

SurfMiner

Miner that reads the field sequentially in waves.

Target

256-bit threshold a block hash must be below; derived from the previous block and the new timestamp.

target_shard

Output field naming the shard the output should live in.

Teapot

Internal name of the public testnet; addresses start with snowtest:.

Trust network (trustnet)

Nodes that sign their chain tips; other nodes may configure which signers to trust for shards they do not validate.

UTXO

Unspent transaction output. Snowblossom's set is a hashed trie keyed by address ‖ tx id ‖ index whose root is in every header.

Work unit

A pool's assignment to a miner: header template, work id, share target.

Work sum

Cumulative chain work, with SIP-2's 4^field weighting; the primary chain-selection criterion.

xpub

Extended public key of an HD wallet account (m/44'/2338'/0'); enough to derive all receive addresses in a watch-only wallet.