Elliptic curve form optimized for fast addition operations, used by Ed25519 (Curve25519 in twisted Edwards form). Solana uses Ed25519 for all keypair generation and transaction signing. The curve's algebraic properties enable complete addition formulas (no edge cases), making implementations simpler and resistant to side-channel attacks.
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Elliptic curve form optimized for fast addition operations, used by Ed25519 (Curve25519 in twisted Edwards form). Solana uses Ed25519 for all keypair generation and transaction signing. The curve's algebraic properties enable complete addition formulas (no edge cases), making implementations simpler and resistant to side-channel attacks.
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Twisted Edwards Curve (twisted-edwards-curve) Category: Core Protocol Definition: Elliptic curve form optimized for fast addition operations, used by Ed25519 (Curve25519 in twisted Edwards form). Solana uses Ed25519 for all keypair generation and transaction signing. The curve's algebraic properties enable complete addition formulas (no edge cases), making implementations simpler and resistant to side-channel attacks. Aliases: Edwards Curve Related: Ed25519, Ed25519 Precompile, On-Curve / Off-Curve
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The elliptic curve digital signature algorithm used by Solana for all transaction signing. Ed25519 uses Curve25519 and produces 64-byte signatures with 32-byte public keys. Solana also provides an Ed25519 precompile program for on-chain signature verification within program logic.
A native Solana program (address: Ed25519SigVerify111111111111111111111111111) that enables batch verification of Ed25519 signatures within on-chain program logic. Unlike the runtime's built-in transaction signature verification, this precompile allows programs to verify arbitrary Ed25519 signatures over arbitrary data, useful for off-chain message verification, oracle attestations, and multi-party protocols. Multiple signatures can be verified in a single instruction.
In elliptic curve cryptography, a point is 'on-curve' if it satisfies the curve equation (e.g., Ed25519) and can serve as a valid public key with a corresponding private key. An 'off-curve' point does not lie on the curve and has no associated private key. Solana Program Derived Addresses (PDAs) are deliberately generated as off-curve points by appending a bump seed, guaranteeing that no private key exists and only the owning program can sign for the address.
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The elliptic curve digital signature algorithm used by Solana for all transaction signing. Ed25519 uses Curve25519 and produces 64-byte signatures with 32-byte public keys. Solana also provides an Ed25519 precompile program for on-chain signature verification within program logic.
A native Solana program (address: Ed25519SigVerify111111111111111111111111111) that enables batch verification of Ed25519 signatures within on-chain program logic. Unlike the runtime's built-in transaction signature verification, this precompile allows programs to verify arbitrary Ed25519 signatures over arbitrary data, useful for off-chain message verification, oracle attestations, and multi-party protocols. Multiple signatures can be verified in a single instruction.
In elliptic curve cryptography, a point is 'on-curve' if it satisfies the curve equation (e.g., Ed25519) and can serve as a valid public key with a corresponding private key. An 'off-curve' point does not lie on the curve and has no associated private key. Solana Program Derived Addresses (PDAs) are deliberately generated as off-curve points by appending a bump seed, guaranteeing that no private key exists and only the owning program can sign for the address.
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A clock mechanism that cryptographically proves the passage of time between events. PoH uses a sequential SHA-256 hash chain where each output becomes the next input, creating a verifiable ordering of events without requiring consensus. The leader produces ~400,000 hashes per slot (~400ms), and any validator can verify the sequence in parallel, enabling Solana's high throughput by removing the need for validators to agree on time.
Solana's custom BFT consensus algorithm built on top of Proof of History. Tower BFT uses PoH as a clock to reduce communication overhead in traditional PBFT from O(n²) to O(n). Validators vote on forks with exponentially increasing lockout periods—each consecutive vote doubles the lockout, making rollbacks progressively more expensive. A fork is finalized when it reaches supermajority (66.7%+ of stake).
A time window during which a designated leader validator can produce a block. Each slot lasts approximately 400 milliseconds. Slots are numbered sequentially from genesis and grouped into epochs of 432,000 slots (~2-3 days). Not every slot produces a block—a skipped slot means the leader was offline or too slow.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.