Bitcoin Forum

Hello, I don't think a lot of people, other than the real developers and hardcore fans :p , are subscribed to the bitcoin-dev mailing list.
About a week ago I read something interesting. It is about Address expiration time added to BIP-173.

Sometimes we have problems when an old address is used by someone who pays us frequently and we could just not want to use that address anymore. If a expiration time is set (and checked by Bob before sending BTC to Alice) we could avoid this uncomfortable situations and, of course, the losing of bitcoins in such transactions.

If you want to read about BIP-173 this is the link to it:
https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki

What do you think about Address expiration settings?

It is a good idea.
As long as the address does still work normally, if you do send coins to it.

Getting a message warning you that the address you are about to pay may not be in use any longer is a good safety check.

How much space does it take in blockchain? Or is it only there if it is used?

I think, if you will use old address - he will activated from archive of blockchain. How soon BIP-173 will be available?

When someone pays frequently, you wouldn't forget to inform him about his new deposit address, so I see no problem there.
When someone pays infrequently, and after 2 years just decides to make another payment without confirming the address with you, that's just dumb :P
Personally, I don't need it. Although I don't follow Satoshi's advice to never delete a wallet to the letter, the only way for someone to ever re-use an address I don't use anymore, is if he randomly finds an old used address on the blockchain and deposits to me. I doubt that will ever happen.

The article is quite technical, but while quickly scanning through it, the word "expiration" isn't mentioned even once. This one does:
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-September/015112.html

There was a lot of discussion about it on the list:
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-September/thread.html

I know I just wanted to bring the discussion to the forum because, as I said before, not a lot of people is subscribed.
Just wanted to make the matter a little bit more public here. At least the forum goes through search engines spiders so people googling for it will read this.

Unfortunately the suggestion isn't timely-- it was made after several parties had publicly deployed BIP173*.  It also has a number of unanswered questions (range and resolution, how do you address that you can't go backwards from a SPK to an expiration...).

I think it's a good idea in general, but I think it will need to wait for the future.

* We seem to have a minor problem in the ecosystem with people aggressively deploying unreviewed draft proposals.

I figured you did, but thought a link might be helpful for others coming here so they could get up to speed.

That breaks the decentralization concept. The benefits of crypto are only as strong as the people and the controls they place on new forks/coins. Any dev that places a control on a token diminishes the initial concept. Some are necessary, like exchanges frameworks of usernames/passwords. But there has to be a limit. Plus, that will auto burn coins at a point.

It can be difficult in a decentralized system to control the behaviors of others.

it is OK to have decentralization that's what there are forums for and mailing list to discuss differences , to resolve them and to get to consensus !
This is what does Bitcoin something that will change the world in the near future.

This post did not get the attention I expected.

"To enjoy freedom we have to control ourselves."

Unfortunately the propensity for people to run off and deploy things without review and discussion with drive a mixture of low quality defacto standards and less inclusive and transparent design work.

Complaining about it a bit is a tool for progress, reminding people to control themselves.  No one need control the behavior of others.