# Stone Markdown version of https://l2beat.com/zk-catalog/stone ## Summary - Creator: Starkware - Total Value Secured: $39.66 M (-0.81% compared to seven days ago) - Trusted setups for STARK: Transparent setup (risk: N/A); used in: [Sorare](https://l2beat.com/layer2s/projects/sorare), [edgeX v1](https://l2beat.com/layer2s/projects/edgex), [tanX](https://l2beat.com/layer2s/projects/tanx), [Myria](https://l2beat.com/layer2s/projects/myria); verifiers: 1 successful - zkVM: Stone (STARK), Cairo ASM (ISA), felt252 (Field) ### About Stone is a proving system for programs written in the Cairo language. Originally built by Starkware for proving Starknet state transition. ## Value Secured Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/zk-catalog/stone#tvs). ## Proof System ### Description Stone is a STARK proof system that is designed to prove the execution of programs written in [Cairo language](https://www.starknet.io/cairo-book/title-page.html) and compiled into Cairo assembly (cASM) byte code. This ISA is highly optimized for the performance of zkVM proving. Stone verifies STARK proofs directly onchain without any final SNARK wraps and thus requires no trusted setup. Stone targets 80 bits of security (e.g. see constructor params on [this contract](https://etherscan.io/address/0x3d57526c1C8D63fa2A8704487Df65e9000166c8E#code)). ### Proof system Stone is a Cairo-based zkVM with AIR arithmetization over [felt252 field](https://docs.starknet.io/archive/cairo-101/felt/) and FRI-based commitment. The protocol makes use of recursive proof aggregation among many projects utilizing the CairoVM (i.e. Starknet forks and StarkEx systems) using SHARP. Some documentation on the aggregation scheme can be found [here](https://docs.starknet.io/architecture/sharp/) and the Cairo verifier implemented in Cairo can be found [here](https://github.com/starkware-libs/cairo-lang/tree/v0.13.1/src/starkware/cairo/cairo_verifier/layouts/all_cairo). #### StarkNet Operating System (SNOS) The base layer of Stone proving is a Cairo program called [SNOS](https://docs.starknet.io/architecture/os/) that proves the correct STF from one state to another given the list of transactions. SNOS execution includes checking transaction inputs (e.g. state), executing transactions and processing state diffs. The source code of the Starknet OS can be found [here](https://github.com/starkware-libs/cairo-lang/tree/ee7ce74e1159a349d4b77a5f952241b50b1692de/src/starkware/starknet/core/os). #### Recursive aggregation Proofs of SNOS executions of several consecutive blocks are recursively aggregated. The correctness of this aggregation is checked by [applicative bootloader](https://github.com/starkware-libs/cairo-lang/blob/8e11b8cc65ae1d0959328b1b4a40b92df8b58595/src/starkware/cairo/bootloaders/applicative_bootloader/applicative_bootloader.cairo#L15) program, which also verifies the correct relation of corresponding SNOS inputs and outputs. Applicative bootloader proofs are aggregated across several blockchains and proven by [SHARP](https://docs.starknet.io/architecture/sharp/#what_is_sharp). The SHARP STARK proof is verified onchain without any SNARK wraps. ## Trusted Setups ### Transparent setup - Risk: N/A - Proof systems: Stone (STARK) Transparent proving systems require no trusted setups and have no additional setup-related trust assumptions. ## Verifier IDs List of different onchain verifiers for this proving system. Unique ID distinguishes different deployments of the same verifier from different verifiers (e.g. different versions). ### STARK: Stone zkVM STARK proving system developed by Starkware for Cairo programs, including state transition of Starknet. #### GPS statement verifier 2026_13_4 Custom verifier ID: SHA256 hash of the address of the immutable verifier smart contract (GpsStatementVerifier) in hex string format '0x...'. - Verifier ID: `0x243611f51b76871574612cc0f140acb660c684a66b74e37b7547474c6683659a` - Source: https://etherscan.io/address/0x4956bda1d23F75B988644329c5B06BD1494a72b6#code - Verification: successful - Used in: [Sorare](https://l2beat.com/layer2s/projects/sorare), [edgeX v1](https://l2beat.com/layer2s/projects/edgex), [tanX](https://l2beat.com/layer2s/projects/tanx), [Myria](https://l2beat.com/layer2s/projects/myria) **Known deployments** - [0x4956bda1d23F75B988644329c5B06BD1494a72b6](https://etherscan.io/address/0x4956bda1d23F75B988644329c5B06BD1494a72b6#code), used in: [Sorare](https://l2beat.com/layer2s/projects/sorare), [edgeX v1](https://l2beat.com/layer2s/projects/edgex), [tanX](https://l2beat.com/layer2s/projects/tanx), [Myria](https://l2beat.com/layer2s/projects/myria) ##### Verification steps Onchain stone verifier smart contracts contain code that directly checks proofs of correct Cairo program execution. Unlike SNARK final wraps, it does not contain any additional cryptographic components that need to be independently regenerated because it introduces no new zk circuits. The sources are verified on etherscan and can be examined directly to check the correct implementation of STARK verification protocol. ## Program Hashes List of known guest zkVM programs used by this prover. Each program represents a piece of offchain execution that is verified onchain. The program hash serves as the program's unique identifier. ### StarkEx program ApeX Pro and EdgeX Cairo program that implements an application-specific L2 with spot and perpetual trading functionality. - Hash: `2530337539466159944237001094809327283009177793361359619481044346150483328860` - Repository: code unknown - Verification: not verified - Used in: [edgeX v1](https://l2beat.com/layer2s/projects/edgex) ### StarkEx program Spot v4.5 Cairo program that implements an application-specific L2 with spot and perpetual trading functionality. - Hash: `16830627573509542901909952446321116535677491650708854009406762893086223513` - Repository: code unknown - Verification: not verified - Used in: [tanX](https://l2beat.com/layer2s/projects/tanx), [Myria](https://l2beat.com/layer2s/projects/myria) ### StarkEx program Spot v4.0 Cairo program that implements an application-specific L2 with spot and perpetual trading functionality. - Hash: `3174901404014912024702042974619036870715605532092680335571201877913899936957` - Repository: code unknown - Verification: not verified - Used in: [Sorare](https://l2beat.com/layer2s/projects/sorare)