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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.

WHAT IS IT? · FOR DUMMIES

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.

WHAT IS IT? · PRO

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.

01 / 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

02 / Advantages

  • Verifiable by anyone, including each client
  • Market discipline: whoever does not publish it says something
  • Cheap to verify compared with a full audit

03 / 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