We are all trying to understand the risks and benefits of using something like Fedimint and Cashu as opposed to purely self-custodial bitcoin (or purely custodial bitcoin a la Wallet of Satoshi).
So here's a table comparing some relevant attributes of these things:
Fedi | Cashu | Liquid | WoS | |
---|---|---|---|---|
Can you be rugged?1 | Yes | Yes | Yes | Yes |
Can you be frozen? | No | No | Maybe2 | Yes |
Permissionless exit? | No | No | No | No |
Can it be frac resrvd? | Yes | Yes | No | Yes |
Single point of failure? | No3 | Yes | No | Yes |
Bearer asset? | Yes | Yes | No | No |
Here's the same table with some other assets:
USDT | gBTC | wBTC | Walmart Gift Card | |
---|---|---|---|---|
Can you be rugged? | Yes | Yes | Yes | Yes |
Can you be frozen? | Yes | Yes | Yes | Maybe4 |
Permissionless exit? | No | No | No | No |
Can it be frac reservd? | Yes | Yes | Yes | Yes |
Single point of failure? | Yes | Yes | Yes | Yes |
Bearer asset? | No | No | No | Yes |
It seems to me that the most important thing that ecash has to offer is its ability to provide permissionless use of the asset within its own ecosystem (it gets this property chiefly from strong privacy guarantees). This is the one property they have that all the other protocols lack.
On every other count, things like Fedi and Cashu look a lot like Liquid, Wallet of Satoshi, or even a stablecoin like Tether.
(I don't think they are like shitcoin tokens because shitcoins don't purport to be pegged to something like dollars or btc, they're speculative. Ecash isn't speculative. You do something like an atomic swap to get into the mint; it's either valued at par with the money you came from or it's worthless.)
Now, here is my probably foolish take: I think ecash looks a lot like gift cards, too.
I can hand you a gift card and you can be pretty sure I am not going to double spend you because it requires a pin which you can visually inspect to see if it has been exposed. Of course the company who issued the gift card can rug you or fractionally reserve the value or go bankrupt and disappear, but so can ecash mints.
Gift cards, like ecash, are designed to be bearer instruments, to be permissionlessly transferrable inside their own ecosystem, and sometimes they even get resold to third parties (at a discount, sure) even if the issuer says they can't.
So, what are we doing when we buy a gift card? Are we having Walmart custody our dollars? I've never heard it described that way. We are purchasing something. Or maybe we are storing value. Stored value is a term that gets brought up in one of the US laws that regulates this stuff, the Consumer Protection Act, 15 U.S.C. §§ 1693-1693r
Ammending that act, Public Law 111-24 has a whole section (Sec. 401) on gift cards, with this particular definition:
(C) Store gift card.--The term `store gift card' means an electronic promise, plastic card, or other payment code or device that is-- (i) redeemable at a single merchant or an affiliated group of merchants that share the same name, mark, or logo; (ii) issued in a specified amount, whether or not that amount may be increased in value or reloaded at the request of the holder; (iii) purchased on a prepaid basis in exchange for payment; and (iv) honored upon presentation by such single merchant or affiliated group of merchants for goods or services.
If you replace the word "merchant" with "fedimint" or "ecash mint," the definition more or less makes sense. As you have no doubt picked up by now, I'm not a lawyer and I'm not even that familiar with ecash stuff. (For instance, I should note that under (D) Exclusions, you find the exclusion of electronic promises, cards, or payment codes which are "(ii) reloadable and not marketed or labeled as a gift card or gift certificate." I'm sure regulators will laugh at my sophistry and send me off to some prison where I will be abused by Bullet-Tooth Tony. Maybe he will take my electronic promises in lieu of more immediate gratification...)
For now, I'm going to say that I am purchasing ecash tokens when I send my sats to a mint.
Okay, that's it. I am prepared for my walk of shame if I have woefully misunderstood this situation. Heft your putrid vegetables and come at me.
Footnotes
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Here are longer versions of the questions I am asking: Can you be rugged? Can you end up losing all the money you came into the protocol with? Can you be frozen? Can you be prevented from moving your money around within the protocol? Permissionless exit? Is there a way to return to the form of money you originally had without needing the permission of the protocol operators? Can it be frac reservd? Can the protocol produce more tokens than are represented by the money they hold? Single point of failure? Is there any one person or business that prevent you from exiting the protocol? Bearer asset? Can you give the token directly to another person without permission from the protocol operator and in a way that you can no longer spend it either? ↩
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Liquid uses a blockchain. Blocks are built and validated by functionaries. Presumably, they could collude to prevent your transactions from entering blocks. ↩
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I'm not sure about this, I'm saying there is no single point of failure because as far as I understand Fedimint, each guardian is keeping a copy of the database and so there is some redundancy against any single guardian failing accidentally or acting against you maliciously. ↩
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Walmart can void any gift card they like, but since identities are not tied to gift cards, they don't necessarily know who has which gift cards. So it would be difficult for them to choose to censor a particular person. ↩