Crypto Wallet Infrastructure: How MPC Custody Works

Crypto wallet infrastructure is the set of systems that generate and store the keys, and sign transactions with them. The hardest part is the key. Whoever holds it controls the coins, so how you hold that key is the whole of custody. MPC custody is the model most institutions moved to, and this guide explains how it works and where its limits are.

What is MPC custody?

MPC custody is a way of holding crypto where the private key is never created or stored as one whole piece. It is split into separate shares held by different parties, and they work together to approve a transaction without the full key ever existing in one place. MPC stands for multi-party computation.

How does MPC custody work?

The private key is the secret that controls the coins. Whoever holds it can move the funds. A standard wallet keeps that key whole, in one place, which makes it a single thing to steal or lose. MPC custody removes that single thing.

Multi-party computation is a branch of cryptography where several parties each hold a piece of a secret and compute a result together without any of them seeing the whole secret. Applied to custody, the key is generated already split into shares, each held by a separate party. To sign a transaction, each party computes part of the signature with its own share, and the parts combine into one valid signature. The full key is never put together, not even for a moment.

A set number of shares has to take part for a signature to count, so no single share, and no single person, can move funds alone.

MPC custody against multisig and single-key wallets

All three hold crypto, but they differ in where the key lives and what can go wrong.

Why does MPC custody matter for a business?

Because it removes the risk that a single lost key or a single insider can drain the treasury. No one person holds the means to move funds, so the coins cannot leave without the required shares taking part. That is the control an auditor looks for, and the reason institutions moved to MPC.

It also stays practical at scale. Because the signing work happens off the chain, a transaction looks and costs like a normal one, and the same method works across many chains rather than depending on each chain’s support for multisig.

Is MPC custody safe, and what are its limits?

MPC custody is strong, but it is not the whole of security. It removes the single-key weakness. It does not replace the controls around it, like the policies for who can request a transaction and how access is managed. Most custody failures come from operational compromise, not broken cryptography. MPC is one strong control, not a complete defence on its own.

How Paybis uses MPC custody

Paybis secures crypto with MPC custody, so the key that controls your company’s crypto is split across parties and never sits whole in one place. It covers the major assets and the main chains a business uses, and it sits inside one account alongside your fiat.

• Assets held. BTC, ETH, SOL, and USDC.
• Chains supported. Ethereum, Polygon, and Base, so the same custody method covers the main chains businesses pay out on.
• No single point of failure. The key is split into shares, so no one person can move funds alone.
• Held in one account. Custody sits inside the Paybis Global Account, so your crypto and your cash are held and seen in one place.
• For your own money. The account is built for a company’s own corporate crypto, not for holding balances on behalf of your customers.

Bottom line

Crypto custody comes down to how you hold the keys. A whole key in one place is one thing to lose. MPC custody splits the key into shares, so no single share, and no single person, can move funds, while a transaction still looks and costs like a normal one. It is the model institutions settled on, and the one Paybis uses to secure a company’s own crypto inside one account.