Key Features

Silica Protocol

The Silica Protocol defines how message data is propagated, validated, and made available across the chain. Instead of embedding message bytes in blocks, data is organized into erasure-coded sidecars that are anchored to the block via cryptographic commitments.

Silica is responsible for:

  • Routing messages into respective lanes

  • Erasure coding each message batch into redundant chunks

  • Peer to peer lane committee gossip

  • Verifying availability through lane committee voting

  • Serving data to requested nodes

Silica operates alongside consensus but does not block it. A block can be finalized even while data propagation is still in progress.

Lane-Based Parallelism

The network is divided into parallel lanes. Each lane has a rotating committee of validators assigned to it. When you submit a message:

  1. It gets routed to a specific lane (based on your address)

  2. The lane's committee validators store chunks of your data

  3. Each validator holds a piece - no single validator has the full message

This distribution model prevents any single validator from becoming a bandwidth bottleneck.

Message Type
Cost
Use Case

Priority (PM)

Bid-based (Signed Debit)

Time-sensitive data, guaranteed fast inclusion

Standard (SM)

VDF proof (compute cost)

Regular messages, fair access

VDF Anti-Spam Protection

Standard Messages require a Verifiable Delay Function proof. VDFs are computations that:

  • Take a minimum amount of sequential time to compute

  • Can be verified quickly

  • Cannot be parallelized or accelerated

This creates a natural rate limit: users must expend real-world time to submit messages, preventing spam floods without requiring monetary fees.

Data Availability & Permanence

Obsidian's approach: the acceptance criteria for messages is committee attestation. Non-committee nodes trust that attestation or can optionally sample for additional confidence.

  • Availability Certificates: A valid certificate proves that a supermajority of the lane committee possessed the data at the time of signing.

  • Erasure Coding: Combined with erasure coding, this guarantees reconstructability from partial data.

  • Retention Window: Committee members are obligated to serve data for a defined retention window after inclusion. After this window, data transitions to archival nodes.

Full EVM Compatibility

Obsidian runs standard Ethereum tooling:

  • MetaMask, Rainbow, and all EVM wallets

  • ethers.js, web3.js, viem

  • Hardhat, Foundry, Remix

  • Data Indexers (The Graph, Ponder, etc.)

  • Smart Contracts (Solidity, Vyper, Huff)

Your Ethereum skills transfer directly.

Sustainable Archive Economics

Obsidian is designed to support sustainable long-term data availability through dedicated archive incentives. This enables:

  • Sustainable incentives for data preservation

  • More messages → more fees → more archive nodes

  • Decentralized historical data availability

Sharded Archive Support

High message throughput creates a storage scaling challenge. At maximum capacity, yearly data growth can reach ~84 TB—far beyond what traditional "store everything" archive nodes can handle.

Obsidian solves this with sharded archives: instead of every archive storing all history, nodes store specific epoch ranges:

  • Accessible participation: Run an archive with consumer hardware by storing a subset of history

  • Horizontal scaling: More epoch ranges served by adding shard groups

  • Redundancy: Multiple nodes per shard group ensures availability

Cryptographic Security

Every message includes:

  • Signature: Proves sender authenticity

  • Chain ID: Prevents cross-chain replay

  • Nonce: Prevents same-chain replay

  • Payload Commitment: Anchored in the canonical block

All verified at multiple layers (RPC, P2P, consensus).

Availability Certificates

An Availability Certificate contains:

  • Reference to the lane batch (slot, lane, sequence)

  • Data commitment (merkle root of chunks)

  • Aggregated committee signatures

  • Signer bitmap (which validators attested)

A valid certificate proves that a supermajority of the lane committee possessed the data at the time of signing. Combined with erasure coding, this guarantees reconstructability.

See: Silica Protocolarrow-up-right.


These features combine to create a blockchain purpose-built for permanent, accessible, decentralized data.

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