When should we deprecate Sprout?

See Do you support deprecating Sprout? for (tons of) context.

In the interest of trying to move the discussion a bit forward, here is a “vibe check” poll to see what people think about when we should deprecate the Sprout pool (with the option open on whether its funds should be burned, moved to NSM, to the lockbox, or whatever)

What is the minimum amount of time we should wait between announcing and effectively deprecating the Sprout pool?

  • ASAP (< 1 year)
  • In 1 year
  • In 2 years
  • In 3 years
  • In 4 years
  • In 5 years
  • In 6-10 years
  • In 10+ years
  • Never!
0 voters
5 Likes

I vote asap.

1 Like

Added that option!

1 Like

Thanks for organizing this poll! I’ll be interested to see the results.

I have a related proposal. You could maybe add it to your poll if you like it.

Instead of all Zcashers collectively accepting Sprout coins at 100% value for N years and then suddenly switching to accepting Sprout coins at 0% value (i.e. not accepting Sprout coins), I would like to see all Zcashers agree that they’ll accept Sprout coins at a discount, like 75% value this year, 50% value next year, 25% value the year after that, and then 0. This is effectively the Zcashers collectively imposing a storage fee on Sprout coins, a fee which goes up every year until the fee consumes the entire principal.

Here’s why I think this proposal would be good for Zcashers:

  1. For holders of Sprout coins, this gives them a second chance if they hadn’t heard of this discussion or didn’t understand what the new rules were going to be, until after the first deadline had passed. I wouldn’t be surprised if there are Sprout holders in this category. They might see a news article about the fee kicking in and then decide to investigate. There may be Sprout holders who will not hear of the “100% → 0%” event until after the event has occurred, but they would hear of the “100% → 75%” event and still have time to save some of their value.
  2. For all Zcashers and devs, it gives a simple and locked-in deadline they can plan around for when they can stop running the code for dealing with Sprout, thus simplifying the code and improving its security and safety. (I.e., when the fee will hit 100%, i.e. the value of Sprout coins will hit 0%.)
  3. For all Zcashers, storage fees sustain and improve Zcash. Even without Shielded Labs’s sustainability programme (Network Sustainability Mechanism + Dynamic Fees + Crosslink), burned fees reduce the supply of ZEC, which (all other things being equal) increases the price. With Shielded Labs sustainability programme, then the burned fees could also go into the NSM to support the security of the network, the 21M supply cap, and the Dev Fund long-term.

And there is a fourth reason I advocate for this, which is a meta-reason:

  1. I want Zcashers to start thinking in terms of fees, not in terms of collective control over features. Collectively controlling or disabling features is not really a repeatable, sustainable process. The users can always just opt out of the disablement and keep using software that provides the feature they want. If they do, this means a chain fork between the fork of the blockchain that kept the feature and the fork of the blockchain that disabled the feature. That might work sometimes – I think it will probably work with Sprout – but I doubt it will ever work to disable Sapling, much less t-addresses. Fees on the other hand, are very unlikely to trigger a chain fork (because we can just collectively agree on a fee low enough to where the people paying the fees would rather pay the fee than do a chain-fork), and in general fees are necessary for any long-running, sustainable economic system.

Fees are necessary for any long-running, sustainable economic system.

If there is something that imposes costs on some people and provides benefits to other people, there are only two ways to manage this: 1. Collectively-decided controls such as limitations, disablement, etc., 2. Collectively-decided fees. Fees impose costs on the ones gaining the benefit at other people’s expense, and fees can be used to compensate the ones bearing the burden.

Fees can be granular, which can be necessary because sometimes 0% is too low and 100% is too high and neither one will work for everyone, which could trigger a failure-to-reach-a-negotiated-agreement, e.g. a chain-fork, but 10% or 50% or 90% would work for everyone. Fees are absolutely better long-term. In fact, they are really the only possible solution long-term. It’s just a fact of economics.

My current position on this: I support disabling Sprout, I’m open to both shorter and longer timelines, but I really want people to think about the meta issue here – whether for Sprout itself or for the next issue: this “all or nothing” process is not repeatable or sustainable. Storage fees are.

By the way, this isn’t an official position of Shielded Labs. I haven’t discussed this post with the Shielded Labs team, and this doesn’t interact with Shielded Labs’s work (except inasmuch as any fees, whether of the 0%→100% in one go variety, or of the more incremental and granular variety, can be fuel for the NSM). I’m just posting this because I’m interested in your poll and in whether you and others would be interested in the “incremental storage fees” variant.

4 Likes

@zooko’s meta-point is the interesting part here.

The specific timeline matters less than the principle. Fees beat hard cutoffs. Gradual fee reduction gives people time to react. It doesn’t require everyone to be paying attention at the exact right moment.

On timing: at least a year of warning before any value loss starts, and at least five years before it reaches zero. If someone loses coins tomorrow because they weren’t following forum discussions, that’s a PR disaster. “Privacy coin confiscates user funds” writes itself as a headline. The technical justification won’t matter.

There’s also a fairness problem. Everyone in this forum knows Sprout deprecation is being discussed. What about holders who aren’t here? They don’t have the same information we do. Making decisions that affect their funds without reaching them first is bad practice.

The gradual fee approach handles both concerns. Each step down is another signal, another reason for wallets and exchanges to notify users. By the time it hits zero, nobody can claim they weren’t warned.

Has anyone mapped out what “broadly distributed warning” actually looks like? Wallet notifications? Exchange announcements? Press coverage? The mechanism matters as much as the timeline.

I think storage fees in general is a neat concept and would support higher fees for transparent transactions. This idea probably deserves its own topic! For sprout, however, too much time has passed and tis time.

I like this idea as a thought experiment - sounds a lot like Ethereum PoW “ice age”! But if Zcash is going for “encrypted money” PMF then demonetizing any coins is, unfortunately, not tenable. Pennies are still a legal tender as are ten-thousand-dollar bills.

6 Likes

That particular point might be a better fit for the other topic: