Engineered for SHA-256d at Global Scale
Our stratum engines are finely calibrated for double-round SHA-256 hashing. Learn about our block header serialization, variable difficulty (VarDiff) algorithms, and protocol framing.
SHA-256d (Double SHA-256)
Primary CoreThe foundational cryptographic hash function securing the Bitcoin network. Consists of two consecutive rounds of SHA-256 cryptographic transformations over an 80-byte block header:
Header Field Breakdown (80 Bytes):
- Version (4 bytes): Block version information
- PrevBlockHash (32 bytes): 256-bit hash of the previous block
- MerkleRoot (32 bytes): Merkle tree root of all transactions
- Timestamp (4 bytes): Unix epoch time
- Bits (4 bytes): Compact difficulty target
- Nonce (4 bytes): Miner search counter
Adaptive VarDiff Engine
Stratum V2To minimize network bandwidth while maintaining microsecond-accurate hashrate accounting, our pool dynamically retargets share difficulty per worker connection.
Target Share Submission Rate
Calculated to provide 5–10 shares per minute per active ASIC.
Minimum Starting Difficulty
Diff 65,536 for small home miners; Diff 2,097,152 for industrial megawatt installations.
Extranonce Roll Buffer
Supports full Version Rolling (Overt ASICBoost) without nonce exhaustion.
Protocol Framing Specifications
| Specification Feature | Legacy Stratum V1 | hash_ce Stratum V2 |
|---|---|---|
| Payload Encoding | Plaintext JSON-RPC | Compact Binary Framing |
| Network Bandwidth | ~250 bytes per share | ~45 bytes per share (-82%) |
| Encryption & Auth | None (Vulnerable to MITM) | Noise Protocol (ChaCha20-Poly1305) |
| Job Negotiation | Pool selects block transactions | Miner can construct own block templates |
Explore our API Reference
Review programmatic endpoints, subscription channels, and live sockets.