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ZK Compression

ZKP Syscall (alt_bn128)

The alt_bn128 syscalls are native BPF VM system calls added to the Solana runtime (via SIMD-0041 and related proposals) that expose elliptic curve operations on the BN254 curve (also known as alt_bn128) — specifically point addition, scalar multiplication, and pairing checks — enabling on-chain programs to verify Groth16 zk-SNARK proofs within practical compute unit budgets. Without these syscalls, implementing the pairing-based verification of a Groth16 proof purely in BPF bytecode would require hundreds of millions of compute units, far exceeding the 1.4M per-transaction limit; with the syscalls, a full Groth16 verification costs on the order of 200,000–400,000 compute units. Light Protocol's on-chain verifier and Solana's Token-2022 Confidential Transfers both depend on the alt_bn128 syscalls, making them a critical piece of Solana's ZK infrastructure.

IDzkp-syscallAliasalt_bn128
Plain meaning

Plain meaning

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The alt_bn128 syscalls are native BPF VM system calls added to the Solana runtime (via SIMD-0041 and related proposals) that expose elliptic curve operations on the BN254 curve (also known as alt_bn128) — specifically point addition, scalar multiplication, and pairing checks — enabling on-chain programs to verify Groth16 zk-SNARK proofs within practical compute unit budgets. Without these syscalls, implementing the pairing-based verification of a Groth16 proof purely in BPF bytecode would require hundreds of millions of compute units, far exceeding the 1.4M per-transaction limit; with the syscalls, a full Groth16 verification costs on the order of 200,000–400,000 compute units. Light Protocol's on-chain verifier and Solana's Token-2022 Confidential Transfers both depend on the alt_bn128 syscalls, making them a critical piece of Solana's ZK infrastructure.

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Compressed state, proofs, and scale-oriented storage patterns.

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ZKP Syscall (alt_bn128) (zkp-syscall)
Category: ZK Compression
Definition: The alt_bn128 syscalls are native BPF VM system calls added to the Solana runtime (via SIMD-0041 and related proposals) that expose elliptic curve operations on the BN254 curve (also known as alt_bn128) — specifically point addition, scalar multiplication, and pairing checks — enabling on-chain programs to verify Groth16 zk-SNARK proofs within practical compute unit budgets. Without these syscalls, implementing the pairing-based verification of a Groth16 proof purely in BPF bytecode would require hundreds of millions of compute units, far exceeding the 1.4M per-transaction limit; with the syscalls, a full Groth16 verification costs on the order of 200,000–400,000 compute units. Light Protocol's on-chain verifier and Solana's Token-2022 Confidential Transfers both depend on the alt_bn128 syscalls, making them a critical piece of Solana's ZK infrastructure.
Aliases: alt_bn128
Related: Zero-Knowledge Proofs (ZKP), Groth16, Solana Virtual Machine (SVM)
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Branch

Zero-Knowledge Proofs (ZKP)

A zero-knowledge proof is a cryptographic protocol by which a prover convinces a verifier that a statement is true — for example, that a state transition is valid — without revealing any information beyond the truth of the statement itself, satisfying the properties of completeness, soundness, and zero-knowledge. In Solana's ecosystem, ZKPs are used by ZK Compression (via Groth16 SNARKs) to prove correct state transitions for compressed accounts without storing full account state on-chain, and by the Token-2022 Confidential Transfers extension (via ElGamal encryption and range proofs) to prove token balances are non-negative without revealing the actual amounts. Solana's BPF VM exposes the alt_bn128 elliptic curve syscall to make on-chain Groth16 proof verification computationally feasible within the 1.4M compute unit budget.

PLONK
Open term
Branch

Groth16

Groth16 is a highly efficient zk-SNARK proving system introduced by Jens Groth in 2016 that produces constant-size proofs (128 bytes: two G1 points and one G2 point on a pairing-friendly elliptic curve) with constant-time verification regardless of circuit complexity, making it the preferred proof system for on-chain verification where calldata and compute costs are constrained. Light Protocol uses Groth16 proofs over the BN254 curve (known as alt_bn128 in Ethereum tooling) to verify compressed account state transitions on Solana, leveraging the native alt_bn128 pairing and point-addition syscalls added to the SVM to keep verification within the per-transaction compute unit limit. The trade-off is that Groth16 requires a trusted setup ceremony per circuit, producing a structured reference string (SRS) whose security relies on participants honestly discarding their toxic waste.

SNARK (Succinct Non-interactive Argument of Knowledge)
Open term
Branch

Solana Virtual Machine (SVM)

The Solana Virtual Machine—the execution environment that runs on-chain programs. SVM loads SBF bytecode, provides syscalls for account access and cryptographic operations, enforces compute budgets, and manages memory. The SVM is being modularized (via the SVM API) to enable use in rollups and other environments outside the main Solana validator.

SealevelBPF (Berkeley Packet Filter)
Open term
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ZK Compression

Zero-Knowledge Proofs (ZKP)

A zero-knowledge proof is a cryptographic protocol by which a prover convinces a verifier that a statement is true — for example, that a state transition is valid — without revealing any information beyond the truth of the statement itself, satisfying the properties of completeness, soundness, and zero-knowledge. In Solana's ecosystem, ZKPs are used by ZK Compression (via Groth16 SNARKs) to prove correct state transitions for compressed accounts without storing full account state on-chain, and by the Token-2022 Confidential Transfers extension (via ElGamal encryption and range proofs) to prove token balances are non-negative without revealing the actual amounts. Solana's BPF VM exposes the alt_bn128 elliptic curve syscall to make on-chain Groth16 proof verification computationally feasible within the 1.4M compute unit budget.

Open term
ZK Compression

Groth16

Groth16 is a highly efficient zk-SNARK proving system introduced by Jens Groth in 2016 that produces constant-size proofs (128 bytes: two G1 points and one G2 point on a pairing-friendly elliptic curve) with constant-time verification regardless of circuit complexity, making it the preferred proof system for on-chain verification where calldata and compute costs are constrained. Light Protocol uses Groth16 proofs over the BN254 curve (known as alt_bn128 in Ethereum tooling) to verify compressed account state transitions on Solana, leveraging the native alt_bn128 pairing and point-addition syscalls added to the SVM to keep verification within the per-transaction compute unit limit. The trade-off is that Groth16 requires a trusted setup ceremony per circuit, producing a structured reference string (SRS) whose security relies on participants honestly discarding their toxic waste.

Open term
Core Protocol

Solana Virtual Machine (SVM)

The Solana Virtual Machine—the execution environment that runs on-chain programs. SVM loads SBF bytecode, provides syscalls for account access and cryptographic operations, enforces compute budgets, and manages memory. The SVM is being modularized (via the SVM API) to enable use in rollups and other environments outside the main Solana validator.

Open term
ZK Compression

ZK Token Proof Program

A native Solana program that verifies zero-knowledge proofs used by Token-2022's Confidential Transfers extension. It validates range proofs (proving encrypted amounts are non-negative and within bounds), equality proofs (proving two ciphertexts encrypt the same value), and ciphertext validity proofs required for confidential token operations. The program uses ElGamal encryption over Ristretto255 and Bulletproofs for range verification, enabling private token transfers where balances and amounts remain encrypted on-chain.

Open term
Commonly confused with

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ZK Compressionalt-bn128-syscall

alt_bn128 Syscall

A native Solana runtime syscall providing elliptic curve operations on the alt_bn128 (BN254) curve — specifically point addition, scalar multiplication, and pairing checks. These operations are essential for on-chain Groth16 zk-SNARK proof verification, which would otherwise exceed the 1.4M compute unit limit if implemented in pure BPF bytecode. Light Protocol's compressed account verification and Token-2022's confidential transfers both depend on the alt_bn128 syscall for ZK proof verification within practical compute budgets.

AliasBN254 Syscall
Open term
ZK Compressionbls12-381-syscall

BLS12-381 Syscall

A Solana runtime syscall that exposes elliptic curve operations on the BLS12-381 pairing-friendly curve, including point addition, scalar multiplication, multi-scalar multiplication, and pairing checks. BLS12-381 is widely used in modern ZK proof systems, Ethereum 2.0 signatures, and other cryptographic protocols. This syscall enables on-chain verification of BLS signatures and ZK proofs that use the BLS12-381 curve without the prohibitive compute cost of a pure BPF implementation.

Open term
ZK Compressionzk-proofs

Zero-Knowledge Proofs (ZKP)

A zero-knowledge proof is a cryptographic protocol by which a prover convinces a verifier that a statement is true — for example, that a state transition is valid — without revealing any information beyond the truth of the statement itself, satisfying the properties of completeness, soundness, and zero-knowledge. In Solana's ecosystem, ZKPs are used by ZK Compression (via Groth16 SNARKs) to prove correct state transitions for compressed accounts without storing full account state on-chain, and by the Token-2022 Confidential Transfers extension (via ElGamal encryption and range proofs) to prove token balances are non-negative without revealing the actual amounts. Solana's BPF VM exposes the alt_bn128 elliptic curve syscall to make on-chain Groth16 proof verification computationally feasible within the 1.4M compute unit budget.

AliasZKPAliasZK Proofs
Open term
Related terms

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ZK Compressionzk-proofs

Zero-Knowledge Proofs (ZKP)

A zero-knowledge proof is a cryptographic protocol by which a prover convinces a verifier that a statement is true — for example, that a state transition is valid — without revealing any information beyond the truth of the statement itself, satisfying the properties of completeness, soundness, and zero-knowledge. In Solana's ecosystem, ZKPs are used by ZK Compression (via Groth16 SNARKs) to prove correct state transitions for compressed accounts without storing full account state on-chain, and by the Token-2022 Confidential Transfers extension (via ElGamal encryption and range proofs) to prove token balances are non-negative without revealing the actual amounts. Solana's BPF VM exposes the alt_bn128 elliptic curve syscall to make on-chain Groth16 proof verification computationally feasible within the 1.4M compute unit budget.

Open term
ZK Compressiongroth16

Groth16

Groth16 is a highly efficient zk-SNARK proving system introduced by Jens Groth in 2016 that produces constant-size proofs (128 bytes: two G1 points and one G2 point on a pairing-friendly elliptic curve) with constant-time verification regardless of circuit complexity, making it the preferred proof system for on-chain verification where calldata and compute costs are constrained. Light Protocol uses Groth16 proofs over the BN254 curve (known as alt_bn128 in Ethereum tooling) to verify compressed account state transitions on Solana, leveraging the native alt_bn128 pairing and point-addition syscalls added to the SVM to keep verification within the per-transaction compute unit limit. The trade-off is that Groth16 requires a trusted setup ceremony per circuit, producing a structured reference string (SRS) whose security relies on participants honestly discarding their toxic waste.

Open term
Core Protocolsvm

Solana Virtual Machine (SVM)

The Solana Virtual Machine—the execution environment that runs on-chain programs. SVM loads SBF bytecode, provides syscalls for account access and cryptographic operations, enforces compute budgets, and manages memory. The SVM is being modularized (via the SVM API) to enable use in rollups and other environments outside the main Solana validator.

Open term
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ZK Compression

State Compression

State Compression is Solana's technique for storing the cryptographic fingerprint (root hash) of a Merkle tree on-chain while keeping the actual leaf data off-chain in the Solana ledger's account data logs, reducing the cost of storing large datasets by orders of magnitude. A compressed NFT collection of 1 million items costs roughly 50 SOL to mint versus ~12,000 SOL with standard SPL accounts, because only a single Concurrent Merkle Tree account occupies on-chain storage. Any data change requires updating the root hash and supplying a Merkle proof to the on-chain program, which verifies inclusion without reading the full dataset.

Open term
ZK Compression

ZK Compression

ZK Compression, pioneered by Light Protocol, extends Solana's state compression model beyond NFTs to general-purpose compressed accounts by using zero-knowledge proofs (specifically Groth16 SNARKs verified via the alt_bn128 syscall) to prove the validity of state transitions without storing full account state on-chain. Compressed accounts live in on-chain Merkle trees but their data is reconstructed from the Solana ledger by indexers like Photon, enabling developers to build applications that use thousands of accounts at a fraction of the normal rent cost — often 1,000x to 5,000x cheaper than regular accounts. The protocol introduces compressed tokens, compressed PDAs, and a system of nullifiers to prevent double-spends while maintaining Solana's throughput.

Open term
ZK Compression

Compressed Account

A compressed account is a Solana account whose state is stored as a leaf in an on-chain Concurrent Merkle Tree rather than as a dedicated on-chain account, making it 100–1,000x cheaper to create and maintain because no rent-exempt lamport balance is required per account. Compressed accounts are identified by a hash of their data and position in the tree; to interact with one, a client must supply a Merkle proof (or rely on the canopy) showing the leaf is part of the current tree root, which the on-chain program verifies before processing the state change. Light Protocol's compressed account model supports arbitrary data, discriminators, and owner programs, making it a general-purpose replacement for expensive on-chain accounts in high-volume use cases.

Open term
ZK Compression

Concurrent Merkle Tree

A Concurrent Merkle Tree (CMT) is a specialized on-chain Solana data structure that allows multiple state updates to the same Merkle tree within a single block without conflicting, by recording a changelog buffer of recent root transitions that validators use to reconcile parallel proof submissions. A CMT is parameterized by its maximum depth (max_depth, determining tree capacity of 2^max_depth leaves), max_buffer_size (number of concurrent changes the changelog can track, directly controlling how many operations per slot the tree can safely absorb), and an optional canopy_depth. The SPL Account Compression program manages CMTs, and they are the foundational storage primitive for both Metaplex compressed NFTs and Light Protocol compressed accounts.

Open term