Glossary OS

Plain meaning

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The practice of signing a Solana transaction on an air-gapped or disconnected device and then broadcasting the signed transaction bytes from an online machine, used to protect private keys from network-exposed environments. Because standard Solana transactions embed a recent blockhash that expires in ~90 seconds, offline signing in practice requires durable nonces to give signers an unlimited preparation window. Offline signing is common in institutional custody, hardware wallet workflows, and high-security treasury management.

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Offline Signing (offline-signing)
Category: Network
Definition: The practice of signing a Solana transaction on an air-gapped or disconnected device and then broadcasting the signed transaction bytes from an online machine, used to protect private keys from network-exposed environments. Because standard Solana transactions embed a recent blockhash that expires in ~90 seconds, offline signing in practice requires durable nonces to give signers an unlimited preparation window. Offline signing is common in institutional custody, hardware wallet workflows, and high-security treasury management.
Related: Durable Nonce, Transaction

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Concept graph

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Branch

Durable Nonce

A mechanism that replaces the short-lived recent blockhash in a transaction with a nonce value stored in a dedicated on-chain nonce account, allowing the transaction to remain valid indefinitely until it is used or the nonce is advanced. The nonce account stores the current nonce hash and an authority; the first instruction of any durable-nonce transaction must be AdvanceNonceAccount, which updates the nonce and invalidates the old one. Durable nonces are essential for workflows requiring offline signing, hardware security modules, or multi-party approval over extended time periods.

Blockhash (Recent)

Open term

Branch

Transaction

An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.

Instruction Signature

Open term

Next concepts to explore

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Network

Durable Nonce

A mechanism that replaces the short-lived recent blockhash in a transaction with a nonce value stored in a dedicated on-chain nonce account, allowing the transaction to remain valid indefinitely until it is used or the nonce is advanced. The nonce account stores the current nonce hash and an authority; the first instruction of any durable-nonce transaction must be AdvanceNonceAccount, which updates the nonce and invalidates the old one. Durable nonces are essential for workflows requiring offline signing, hardware security modules, or multi-party approval over extended time periods.

Open term

Programming Model

Transaction

An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.

Open term

Network

Parallel Transaction Execution

Solana's ability to process multiple transactions simultaneously by analyzing their account access lists and executing non-conflicting transactions in parallel across CPU cores via the Sealevel runtime. Two transactions can run in parallel only if they do not share any writable accounts; transactions sharing a writable account are serialized. This design allows Solana to fully exploit modern multi-core hardware and is a primary contributor to its high throughput.

Open term

Network

Node Count

The total number of validators participating in a Solana cluster at a given time. Node count is a measure of network decentralization and resilience — more validators mean greater geographic distribution and fault tolerance. Solana mainnet-beta typically operates with 1,500-3,000+ validators. Node count is queryable via the getClusterNodes RPC method.

Open term

Related terms

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Networkdurable-nonce

Durable Nonce

A mechanism that replaces the short-lived recent blockhash in a transaction with a nonce value stored in a dedicated on-chain nonce account, allowing the transaction to remain valid indefinitely until it is used or the nonce is advanced. The nonce account stores the current nonce hash and an authority; the first instruction of any durable-nonce transaction must be AdvanceNonceAccount, which updates the nonce and invalidates the old one. Durable nonces are essential for workflows requiring offline signing, hardware security modules, or multi-party approval over extended time periods.

Open term

Programming Modeltransaction

Transaction

An atomic unit of execution containing one or more instructions, a recent blockhash, and one or more signatures. All instructions in a transaction execute sequentially and atomically—if any instruction fails, the entire transaction reverts. Transactions have a 1,232-byte size limit (matching IPv6 MTU) and a default 200,000 CU budget.

Open term

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Network

Mainnet Beta

Solana's primary production cluster where real SOL and real economic activity occur; the "beta" designation reflects the network's ongoing protocol development despite being fully live since March 2020. It uses the same architecture as other clusters but with real validator stakes, live staking rewards, and permanent on-chain state. All production dApps, tokens, and NFTs exist on Mainnet Beta.

Open term

Network

Devnet

A persistent public Solana cluster intended for application development and testing, running the same software version as Mainnet Beta but with no real economic value. Devnet SOL can be freely airdropped via the CLI or faucet APIs, and the ledger may be reset periodically by Solana Labs. Developers use Devnet to test programs and integrations before deploying to Mainnet Beta.

Open term

Network

Testnet

A public Solana cluster used primarily by the Solana core team and validators to test new software releases, performance benchmarks, and network upgrades under real network conditions before they reach Mainnet Beta. Testnet SOL has no monetary value, and the ledger is reset more frequently than Devnet; it is less suitable for application development and more suited for validator operators validating their infrastructure.

Open term

Network

TPS (Transactions Per Second)

The rate at which a Solana cluster processes and commits transactions; Solana's theoretical maximum exceeds 65,000 TPS due to its parallel execution model, though real-world sustained throughput on Mainnet Beta typically ranges from 2,000–5,000 non-vote TPS under normal load. Vote transactions (used for consensus) make up a significant portion of all on-chain activity and are counted separately. High TPS is enabled by Proof of History timestamps, Sealevel parallel execution, and Gulf Stream mempool-less forwarding.

Open term