GLOSSARY · BLOCKCHAIN & WEB3
Proof of Reserves
What proof of reserves is: how a custodian or issuer cryptographically demonstrates that it backs its clients' balances, and the limits of the method.
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What is proof of reserves?
A serious proof of reserves combines proof of assets (verifiable addresses or a third-party attestation) with proof of liabilities — typically a Merkle tree of client balances that lets each user check that their balance is included without exposing the rest. Without the liabilities leg, the proof is decorative: showing funds says nothing about how much is owed.
Its limits matter: it is a snapshot, it does not watch off-chain liabilities or hidden loans, and it does not replace the audit and regulated segregation that MiCA requires of custodians and issuers — the standard we describe in crypto-asset custody and in the euro stablecoin.
Learn more: Crypto custody providers: institutional solutions and how to choose one
Explained simply
Proof of reserves is how an exchange, custodian or stablecoin issuer demonstrates that it really holds the assets it claims to hold: it publishes cryptographic proofs of its balances so that anyone can verify them. It was born from an expensive lesson: promises of solvency without proof are worth nothing.
Proof of Reserves: key points
- Cryptographic proof that a custodian/issuer backs client balances
- Complete: verifiable assets + liabilities in a Merkle tree
- A snapshot: it does not detect hidden off-chain debts
- Complements — does not replace — regulated audit and segregation
Proof of Reserves: advantages
- Verifiable by anyone, including each client
- Market discipline: whoever does not publish it says something
- Cheap to verify compared with a full audit
Proof of Reserves: disadvantages
- A snapshot, manipulable with funds borrowed that day
- Does not cover hidden off-chain liabilities
- False sense of security if read as an audit