Clear DefinitionsProof of Retrievability
1 min read
Pronunciation
[proof of ree-tree-vuh-bil-i-tee]
Analogy
Like asking a storage warehouse to prove it still holds your goods by showing a small sample tag rather than shipping everything back.
Definition
A cryptographic protocol enabling a client to verify that a remote storage server retains intact a file by issuing challenges and checking short proofs without retrieving the entire file.
Key Points Intro
PoR ensures data integrity and availability in outsourced storage.
Key Points
Challenge-response: Client requests proof of random file segments.
Spot checking: Verifies small portions represent whole file.
Efficient: Low bandwidth compared to full download.
Proof generation: Server computes Merkle proofs or homomorphic tags.
Example
Technical Deep Dive
File split into blocks, build Merkle tree root R stored on-chain. Client sends random index i, server returns block_i and Merkle proof. Client verifies `hash(block_i)` with path to R.
Security Warning
Predictable challenge patterns can allow partial deletion; use verifiable random functions.
Caveat
Frequent challenges increase overhead; balance frequency with assurance.
Proof of Retrievability - Related Articles
No related articles for this term.