A Seed Phrase Isn’t Self Custody, It’s A Liability.

For as long as bitcoin has existed, self-custody–the ability to transact with and hold your own wealth without the need for a third party intermediary like a bank or other financial institution–has been central to the offer. 

For some, self custody is a firmly-held belief in the right to “be your own bank.” For others, it’s a practical step taken to safeguard a valuable asset that can be–and has been–lost to exchange hacks, mismanagement, or FTX-style collapse. A bit like keeping a safe full of cash at home, if there’s a run on the “bank,” your coins are immune. 

And while the “how” of self custody has changed forms throughout bitcoin’s history, today’s de facto industry standard for recovery–the seed phrase–often leaves users at a (sometimes enormous) loss when things go wrong. 

A Distinction Without A Difference

In the early days of bitcoin, there was only self custody. At the risk of oversimplying, self custody meant managing private key material–a string of 64 random characters that gave whoever held it access to the underlying bitcoin. Tools for managing private keys were pretty limited: memorize them or write them down and store them somewhere safe. But put just one character out of place, and oops, your key doesn’t work. Even if you do everything right, there’s still the very real possibility of loss–to theft, accident, or disaster. 

Seed phrases meant to make private keys easier to manage. Instead of securing long strings of random characters, Bitcoin Improvement Proposal-39 (BIP-39) let a handful of simple words essentially stand in for a private key. As long as you have the right sequence of words, you’ll always get the same private key and have access to your funds. 

While it is definitely easier to deal with a few common words than a long string of characters, the risk of loss through human error, theft, or disaster is essentially the same with a seed phrase as it ever was with private keys. For anyone who has lost a backup when they really needed it, it’s a distinction without a difference. When it’s gone, it’s gone, and there’s no getting it back. 

Moving Beyond Stone Age Security For Space Age Assets 

Somewhere along the way, the whole idea of self-custody became synonymous with seed phrases in a lot of people’s minds. But self custody isn’t an object; it’s a capability. And seed phrases are a lot more liability than they are capability. 

Sure, a seed phrase lets you regenerate your keys or easily move your funds to another wallet, but it lets anyone who sees it even briefly do that, too. It’s a nuclear option–one that grants anyone who holds it access to its entire payload. That’s why most people who use them are forced to rely on pretty archaic security measures to protect them: bury them, use book ciphers, distribute copies and bury those, stamp them on increasingly heat-resistant alloys, and so on. 

But the idea that the…