The core mechanism of Proof of History. A SHA-256 hash is computed sequentially—each hash takes the previous hash as input—creating an ordered, unforgeable timestamp sequence. The PoH generator runs approximately 400,000 hashes per slot. Data (transactions) can be inserted into the chain by mixing their hash with the current state.
Empieza por la explicación más corta y útil antes de profundizar.
The core mechanism of Proof of History. A SHA-256 hash is computed sequentially—each hash takes the previous hash as input—creating an ordered, unforgeable timestamp sequence. The PoH generator runs approximately 400,000 hashes per slot. Data (transactions) can be inserted into the chain by mixing their hash with the current state.
Usa primero la analogía corta para razonar mejor sobre el término cuando aparezca en código, docs o prompts.
Piensa en esto como parte del engranaje que mantiene funcionando el orden, la ejecución o el consenso de la red.
Ubica el término dentro de la capa de Solana en la que vive para razonar mejor sobre él.
Consenso, rotación de líderes, slots, epochs y el runtime.
Convierte el término de vocabulario en algo operacional para producto e ingeniería.
Este término desbloquea conceptos adyacentes rápido, así que funciona mejor cuando lo tratas como un punto de conexión y no como una definición aislada.
Usa este bloque compacto cuando quieras dar contexto sólido a un agente o asistente sin volcar toda la página.
Cadena de Hash SHA-256 (sha256-hash-chain) Categoría: Protocolo Base Definición: The core mechanism of Proof of History. A SHA-256 hash is computed sequentially—each hash takes the previous hash as input—creating an ordered, unforgeable timestamp sequence. The PoH generator runs approximately 400,000 hashes per slot. Data (transactions) can be inserted into the chain by mixing their hash with the current state. Relacionados: Prueba de Historia (PoH), VDF (Función de Retardo Verificable), Tick
Usa contexto del glosario, relaciones entre términos, modelos mentales y builder paths para recibir respuestas estructuradas en vez de output genérico.
Opcional: pega código Anchor, Solana o Rust para que el Copilot mapee primitivas de vuelta al glosario.
El Copilot responderá usando el término actual, conceptos relacionados, modelos mentales y el grafo alrededor del glosario.
Estas ramas muestran qué conceptos toca este término directamente y qué existe una capa más allá de ellos.
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.
Verifiable Delay Function—a function that takes a prescribed amount of sequential computation to evaluate but whose output can be quickly verified. Solana's Proof of History uses a SHA-256 hash chain as a practical VDF: computing the chain is inherently sequential, but verifying any segment can be parallelized across multiple cores.
A PoH entry with zero transactions that advances the clock. There are 64 ticks per slot by default, each representing a fixed number of SHA-256 hash iterations. Ticks establish the passage of time even when no transactions are being processed, maintaining the PoH chain continuity.
Estos son los siguientes conceptos que vale la pena abrir si quieres que este término tenga más sentido dentro de un workflow real de Solana.
Las entradas del glosario se vuelven útiles cuando están conectadas. Estos enlaces son el camino más corto hacia ideas adyacentes.
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.
Verifiable Delay Function—a function that takes a prescribed amount of sequential computation to evaluate but whose output can be quickly verified. Solana's Proof of History uses a SHA-256 hash chain as a practical VDF: computing the chain is inherently sequential, but verifying any segment can be parallelized across multiple cores.
A PoH entry with zero transactions that advances the clock. There are 64 ticks per slot by default, each representing a fixed number of SHA-256 hash iterations. Ticks establish the passage of time even when no transactions are being processed, maintaining the PoH chain continuity.
Estas entradas viven junto al término actual y ayudan a que la página se sienta parte de un grafo de conocimiento más amplio en lugar de un callejón sin salida.
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.