ZeusLayer in a Nutshell

ZeusLayer Overview

ZeusLayer is a cutting-edge platform that bridges Bitcoin and Solana ecosystems, enabling seamless interaction between Bitcoin’s robust security and Solana’s high-performance decentralized finance (DeFi) infrastructure. This document provides a comprehensive overview of ZeusLayer, detailing its ecosystem, technical breakthroughs, reserve designs, operational lifecycle, and key components. Figure 1 illustrates the ZeusLayer ecosystem.

ZeusLayer facilitates Bitcoin-Solana interoperability through a suite of decentralized applications (dApps), a tokenized Bitcoin asset (zBTC), and a robust delegation system. The platform supports several key applications, including Apollo, BTCSol, and LightningFi. The $zBTC, minted on Solana, enables Bitcoin-backed assets to participate in Solana’s DeFi ecosystem. The ZeusDelegator manages delegation processes, while ZeusScan provides real-time interaction data for transparency and verification.

Our Technical Breakthroughs

ZeusLayer leverages several innovative open-source libraries to achieve its functionality, primarily developed in Rust for cryptographic efficiency and compatibility with Solana. These libraries form the backbone of ZeusLayer’s cryptographic operations, ensuring secure and efficient Bitcoin-Solana interactions. Key technical contributions include:

• solana-secp256k1: A Solana-compatible implementation of the secp256k1 elliptic curve
• solana-secp256k1-ecdsa: ECDSA signature support for secp256k1 on Solana
• solana-secp256k1-schnorr: Schnorr signature implementation for Solana
• solana-nostd-secp256k1-recover: A no-standard-library recovery mechanism for secp256k1
• Logos: An isomorphic Rust/WASM/SVM library for Bitcoin and Taproot

Metrics (As of May 19, 2025)

ZeusLayer’s performance is reflected in its key metrics (updated as of May 19, 2025). These metrics highlight ZeusLayer’s growing adoption within the DeFi ecosystem:

• zBTC minted: 266.98 zBTC
• Distribution and DeFi Allocation
  • Fragmetric: 78.60 zBTC (29.62% of total circulation)
  • Orca: 27.84 zBTC (10.49% of total circulation)
  • Meteora: 4.93 zBTC (1.86% of total circulation)
  • Stabble: 3.14 BTC (1.18% of total circulation)
  • Save: 2.71 zBTC (1.02% of total circulation)
  • Raydium: 1.37 zBTC (0.51% of total circulation)
• Largest Transactions
  • Largest Deposit: 40 BTC
  • Biggest Withdrawal: 5 BTC

Bitcoin Taproot TL; DR

ZeusLayer leverages Bitcoin’s Taproot upgrade to enhance privacy and flexibility in its reserve designs. Taproot introduces two spending paths: Key-path Spend (using a single public key) and Script-path Spend (using a script with conditions). Conceptually, these can be likened to a door with physical lock (key-path) and an electronic lock (script-path). For further details on Taproot, refer to learn-me-a-bitcoin.

Source: https://learnmeabitcoin.com/technical/upgrades/taproot/

Reserve Design

ZeusLayer employs two primary script types to secure Bitcoin assets: Pay-to-Taproot (P2TR) and Pay-to-Script-Hash (P2SH).

P2TR (Taproot) Reserves

P2TR reserves utilize Taproot’s dual spending paths for flexibility and security:

• Hot Reserve
  • Key-path: Uses a Guardian Internal X-only Public Key with Multi-Party Computation (MPC).
  • Script-path: Includes a CHECKSEQUENCEVERIFY (CSV) Opcode with a user’s X-only Public Key and a 7-day locktime (144 * 7 blocks).
• Cold Reserve
  • Key-path: Uses a Guardian Internal X-only Public Key with Multi-Party Computation (MPC).
  • Script-path: Includes a CHECKSEQUENCEVERIFY (CSV) Opcode with a Guardian Counterparty Recovery Key and a locktime of at least 90 days (144 * m, where m ≥ 90). An optional script allows recovery by the Zeus Foundation after 90 days.
• Entity-derived Reserve
  • Key-path: Uses a Guardian Internal X-only Public Key with Multi-Party Computation (MPC).
  • Script-path: Incorporates a user’s Solana Public Key, an Application Label, and a CHECKSEQUENCEVERIFY (CSV) Opcode with a Guardian Counterparty Recovery Key and a locktime of at least 90 days (144 * m, where m ≥ 90).

P2SH Reserves

• Redeem Script
  • <Solana PublicKey Hash> OP_DROP OP_DUP OP_HASH160 <Bitcoin PublicKey Hash> OP_EQUALVERIFY OP_CHECKSIG
  • Need User’s Solana public Key
• Locking Script
  • OP_HASH160 <script_hash> OP_EQUAL
• Unlocking Script
  • <Data> <Redeem Script>

Lifecycle of ZeusLayer Interaction

Live interaction data is available at ZeusScan.

Deposit Flow

The deposit process involves a user sending BTC to a ZeusLayer reserve, which is verified and minted as zBTC on Solana.

Withdrawal Flow

Withdrawals reverse the process, converting zBTC back to BTC via the reserve.

Roles

• Operator (ZeusNode): Manages transaction verification and blockchain interactions.
• Guardian (Signing Entity): Secures reserves through multi-party computation.

Architecture

Key modules of ZPL

• BitcoinSPV: Validates Bitcoin transactions using Simplified Payment Verification.
• TwoWayPeg: Manages the pegging of BTC to zBTC and vice versa.
• LiquidityManagement: Manages the vaults and positions of zBTC.
• Delegator: Handles delegation logic for ZeusDelegator.

BitcoinSPV Working Flow

1. User deposits BTC to ZeusLayer Reserve
2. Bitcoin Block is mined
3. ZeusLayer Oracle extends a Bitcoin Block B1 after n confirmations

pub const BLOCK_HEADER_BYTES: usize = 80;

pub struct Blockchain {
  pub network_kind: NetworkKind,
  pub chain_symbol: String,
  pub genesis: [u8; BLOCK_HEADER_BYTES],
  // Current best amount of work
  pub chainwork: [u8; BLOCK_HASH_BYTES],
  // Recent block hashes
  pub recent_block_hash: [u8; BLOCK_HASH_BYTES],
  // The current difficulty target
  pub bits: u32,
  // Most recent difficulty epoch
  pub epoch: u32,
  // Most recent block time
  pub timestamp: u32,
  // Current block height
  pub height: u32,
  }

pub const BLOCK_HEADER_BYTES: usize = 80;

pub struct BlockHeader([u8; BLOCK_HEADER_BYTES]);

• To validate our header chain, we need to ensure:
  1. We have n existed headers
  2. They each have a valid PoW
  3. They form a valid chain of blocks
  4. Difficulty adjustments are handled correctly
  5. Their difficulty target is correct
• If this holds true, then:
  1. Increment block height
  2. Update the timestamp
  3. Update bits if a difficulty adjustment has occurred
  4. Update the recent block hash
  5. Extend chainwork

4. ZeusLayer Operator (ZeusNode) identifies Bitcoin TransactionID Tx1 of a certain User
5. ZeusLayer Operator (ZeusNode) verifies if Tx1 is included in the extended block B1
6. Solana account VerifiedTransaction is created if SPV Proof is valid

pub const BLOCK_HASH_BYTES: usize = 32;
pub const TRANSACTION_ID_BYTES: usize = 32;

pub struct VerifiedTransaction {
  pub block_height: u32,
  pub transaction_index_in_block: u32,
  pub block_hash: [u8; BLOCK_HASH_BYTES],
  pub transaction_id: [u8; TRANSACTION_ID_BYTES],
}

Zeus Ecosystem dApps / Tools

The ZeusLayer ecosystem includes several dApps and tools:

dApps

• Apollo
• btcSOL
• LightningFi

Tools

• ZeusScan
• Zeuselegator

ZeusStack: Plug Native Bitcoin into Solana DeFi

ZeusStack is the development framework powering ZeusLayer’s integration of Bitcoin into Solana DeFi.

Core Library

• Logos: Isomorphic Rust/WASM/SVM library for Bitcoin and Taproot
• Eris: Bitcoin RPC Client written in Rust
• Solana-*: Primitive cryptographic libraries

ZeusLayer

• ZeusNode: A node that manages transaction verification and blockchain interactions
• ZPL: Zeus Program Library

Application SDK

• ZPL SDK: SDK of Zeus Program Library
• Orpheus: A Next.js template for Bitcoin applications built on ZeusLayer

Dev Tools (API / CLI)

• Hermes: API of ZeusLayer Indexing Service
• Ares: Bitcoin API Gateway written in Rust
• Leto: CLI for interacting with ZeusLayer
• Metis: CLI for stress tests