Proof of Reserves (PoR) is a verification approach used by crypto exchanges, custodians, and other centralized platforms to demonstrate they hold the digital assets they claim to hold on behalf of users. It combines cryptographic techniques with an audit or attestation process to improve transparency around custody and solvency.
How Proof of Reserves works
In a typical PoR process, a platform proves control of certain on-chain wallets by signing messages or moving small amounts of funds, then publishes wallet addresses so anyone can view balances on a blockchain explorer. To protect user privacy while still proving customer balances are included, many platforms use a Merkle tree. Each user can check a “Merkle proof” that their account balance was included in the platform’s total reported liabilities, without exposing other users’ data.
A practical example is an exchange publishing its reserve addresses for major assets and providing a tool where customers verify their balance is part of the audited snapshot. An independent third party may validate the methodology and confirm the platform controls the wallets shown.
What PoR does and does not guarantee
PoR is most useful when it includes both reserves (assets held) and liabilities (what the platform owes users), ideally with clear methodology and third-party oversight. However, PoR can be limited by snapshot timing, meaning reserves can look healthy at a single point in time. It may also fail to capture off-chain obligations, borrowed funds, rehypothecation, or fiat balances held in traditional bank accounts unless those are separately audited. Incomplete liability reporting can also weaken the value of a PoR.