Strata (Alpen Labs)
ZK rollup on Bitcoin developed by Alpen Labs. Aims to be a flexible execution environment with EVM compatibility and a trust-minimized bridge to Bitcoin.
Architecture
- Off-chain execution (zkEVM-style).
- Validity proofs committed to Bitcoin.
- BitVM-class bridge for trust-minimized peg-in/out.
- Sequencer for ordering txs (initially centralized, decentralizing).
Status
- Active development; testnet phases through 2025-2026.
- Mainnet: pending (check current docs).
- Comparable goals to Citrea but distinct implementation choices.
Use cases
- DeFi: Solidity contracts on Bitcoin.
- Cross-chain bridges for assets.
- High-throughput payment apps that need EVM-style programmability.
Comparison
| Aspect | Strata | Citrea | BSquared |
|---|---|---|---|
| Status (early 2026) | Testnet → mainnet pending | Mainnet (Jan 2026) | Live |
| ZK system | zkVM | zkEVM type-2 | zk + optimistic hybrid |
| Bridge | BitVM | BitVM2 | Federation + zk |
| Backing | Alpen Labs | Citrea team | B² Network |