Op_checklocktimeverify


#1

#2

For those not technically inclined, what does this mean?


#3

Having only scanned it, it appears to me as something that can e.g. be used for implementing Proof-of-Park.
Maybe someone can verify this (or put me on the right track).


#4

@Sentinelrv
“allows a transaction output to be made unspendable until some point in the future”
It rearranges contract definition, making it simpler and more secure to use them. With it, contract is described in transaction output(stored in blockchain- to recover funds you only need a private key[paper-wallet]) instead of being spread(and dependent) onto multiple transactions/signatures(which need to be stored by both sides of contract[custom storage, difficult spending]).

Taking micropayments as an example
Currently: Payor asks Payee to sing his refund, Payee singns and returns refund to Payor, Payor publish deposit tx and hopes that his deposit isn’t malleable - if it is, he may lost his funds forever.
With new opcode: Payor creates tx and publish it, his funds are safe. Payee (service provider) is happy because he doesn’t have to handle additional requests(“sign my refund”), his service is more reliable and easy to maintain.

I think that it’s a KILLER-OPCODE mostly for Peercoin and pegged currencies.

@masterOfDisaster
IDK what is Proof-Of-Park but I guess it’s NuBits related. It’s definitely easiest way to park the funds I think.


#5

I picked up the term Proof-of-Park somewhere.
The idea is to limit access to certain resources (e.g. registering account names at websites) by the need to prove something - in this case to prove that you have parked coins.

Example use case:
currently there are CAPTCHAs in place as a protection to prevent the websites from being spammed with automatically generated accounts.
You could replace that mechanism with OP_CHECKLOCKTIMEVERIFY by requiring a transaction to complete the registration process .
You have proved that you “parked” some coins (making them unspendable for some time) -> Proof-of-Park.


#6

Bump, huge opportunity for ppc to take a lead in micropayments and contracts field.


#7

Looks like BIP-0065 is getting near universal approval, better not miss the train Peercoin!

Source: https://twitter.com/jgarzik/status/532497686008967168

UPDATE: soon available in ppcd as it’s already being implemented in btcd: https://twitter.com/dajohi/status/532619259382611968


#8

Interesting readings about BIP-0065 / CHECKLOCKTIMEVERIFY:

Bitcoin mailing list: http://sourceforge.net/p/bitcoin/mailman/message/33087789/

https://www.cryptocoinsnews.com/checklocktimeverify-means-bitcoin-escrow-refunds-fork/
http://www.reddit.com/r/Bitcoin/comments/2i6pz0/peter_todds_checklocktimeverify_means_bitcoin/


#9

#10

Nice interview of Peter Todd about his BIP-65 OP_CHECKLOCKTIMEVERIFY proposal:

http://cointelegraph.com/news/113184/peter-todd-and-the-expansion-of-bitcoin


#11

[quote=“mably, post:10, topic:3067”]Nice interview of Peter Todd about his BIP-65 OP_CHECKLOCKTIMEVERIFY proposal:

http://cointelegraph.com/news/113184/peter-todd-and-the-expansion-of-bitcoin[/quote]
TY Mably!

Where this gets really exciting is the hub-and-spoke model: If Alice, Bob, and Charlie all have micropayment channels with a shared hub, they can effectively send money to each other instantly and trustlessly by sending a small amount to the hub; and having the hub in-turn resend it to the final destination. This enormously increases the scalability of Bitcoin as all these transactions happen off the blockchain, yet the hub never actually has control of the money.

That’s what I’d like to see with Peercoin, that’s somehow my dream for not-so-few months.
With some protocol modifications it would be possible to have money “on hub” and still be able to mint, it’s uber-exciting.


#12

bump


#13

Check Sequence Verify( relative lock-time) activated on Bitcoin 11 days ago


#14

Wow, we were just talking about the fact you’ve been missing for a while the other day in chat. It was in reference to writing an expanded version of the Peercoin whitepaper and the fact that we would need people that are knowledgeable about the protocol such as yourself to help us if we wanted to have any chance of completing it. It’s just an idea at this stage though.

Anyway, don’t let me derail the thread.


#15

Thanks [member=2673]irritant[/member] for bringing this thread to my attention.

I fully agree that we need to have these two OP_CODES in peercoin. These are still missing pieces in our Script system.
I will try to merge and test the following pull requests into the ppcoin code:

https://github.com/bitcoin/bitcoin/commit/41076aad0cbdfa4c4cf376e345114a5c29086f81
https://github.com/bitcoin/bitcoin/pull/7184/files