Self-custody wallet

A crypto wallet whose private keys are held by the user alone, rather than by a platform on the user's behalf. It is what a DEX connects to, and it means there is no provider who can restore access.

Definition

A self-custody wallet holds the keys that authorise transactions from an address, and holds them nowhere else. There is no account with the wallet provider, no password reset, and no support desk with the ability to intervene, because the provider has nothing to intervene with.

Why a DEX requires one

Trading on a decentralised exchange means signing transactions from your own address. There is no account to open and no identity check to pass, so connecting a wallet is the whole of the onboarding.

That is the substantive difference from a centralised exchange, and it cuts both ways. Your funds are not on a platform’s balance sheet and cannot be frozen by it. They are also not covered by anything the platform could offer if you lose access.

What the responsibility actually consists of

The seed phrase, which is the master key to the wallet and must never be entered anywhere except when restoring the wallet itself.

The signature prompt, which is where most losses now happen. Approving a malicious transaction moves your assets legitimately as far as the chain is concerned, and a wallet drainer is built to make that approval look ordinary. Reading what you are signing is not optional caution, it is the security model.

And the token approvals you have granted over time, which stay live until revoked and can be exploited long after you have forgotten the site that asked for them.

Hot and cold

A wallet whose keys sit on an internet-connected device is convenient and permanently exposed to that device. A hardware wallet keeps the keys offline and requires physical confirmation for each signature, which is the meaningful protection for balances you would not want to lose.

The two are not exclusive: a common arrangement is a small hot wallet for active trading and a hardware wallet for the rest.

Where you will run into it

At the connect step of every DEX, and behind every mention of custody in a comparison between a DEX and a centralised exchange.