> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kontor.network/llms.txt
> Use this file to discover all available pages before exploring further.

# Kontor Proof-of-Retrievability

The Proof-of-Retrievability specification details the cryptographic system underlying the storage protocol's challenge-response mechanism.

<a href="https://storage.googleapis.com/kontor-docs-assets/crypto/kontor-crypto_2026-01-10.pdf" target="_blank" className="block">
  <Card title="Kontor Proof-of-Retrievability Specification" icon="file-pdf">
    Read the complete cryptographic specification for storage proofs (PDF)
  </Card>
</a>

## Key Topics Covered

* Multi-file proof aggregation with File Ledger construction
* Challenge derivation from Bitcoin block entropy
* Nova IVC circuit design with Poseidon hashing
* Spartan SNARK compression for compact proofs
* Security analysis and computational assumptions