ARC-0008 - Support Snark Verification in Aleo Programs

[raychu86]

---

arc: 0008
title: Support Snark Verification in Aleo Programs
authors: @raychu86
discussion: #102
topic: Protocol
status: Draft
created: 11-28-25

---

Abstract

This ARC proposes adding new Snark verification opcodes (i.e. snark.verify and snark.verify.batch) to Aleo programs. These opcodes enable the verification of SNARK proofs, specifically Varuna proofs, within the finalize scope of a program. This enhancement enables native, intra-program proof verification and lays the foundation for modular proof composition directly on Aleo.

Motivation

The ability to verify SNARK proofs inside Aleo programs unlocks powerful new patterns in application design. Developers can:

• Build programs that verify external computation.
• Compose proofs from multiple sources on-chain.
• Reduce trust assumptions by embedding verification directly into on-chain program execution.
• This functionality also improves interoperability, allowing proofs produced off-chain or by other systems to be verified natively on Aleo.

Specification

This ARC introduces new finalize-only opcodes - snark.verify.*

Currently, the opcodes variants verify Varuna proofs and return a boolean result.

Because verifying keys and proofs can be large, this ARC also increases the maximum allowed array size from 512 to 2048 elements.

Examples

snark.verify

snark.verify r0 r1 r2 into r3

Inputs

- r0 - Verifying key ([u8])
- r1 - Verifier inputs ([field])
- r2 - Proof ([u8])

Output
- r3 - Verification result (boolean)

snark.verify.batch

snark.verify.batch r0 r1 r2 into r3

Inputs
- r0 - Array of verifying keys (2D byte array)
- r1 - Array of verifier inputs (3D byte array - [[[field]; num_batches_on_same_key]; num_keys])
- r2 - Batch proof ([u8])

Output
- r3 - Batch verification result (boolean)

Reference Implementation

An implementation can be viewed here for your review - aleo-labs-protocol/snarkVM#3004

Backwards Compatibility

This ARC introduces new finalize-only opcodes and an increased array capacity. A network upgrade is required to activate the feature, tied to a new Consensus Version. No breaking changes to existing programs are expected.

Future Work

Future extensions may include support for additional ZK proof systems and/or more generalized proof verification APIs.