Thanks informasinya.

Saya sedang mendalami cross-chain protocol (CCP), di antaranya 2-way peg (2WP) nya Back, dan tentunya Liquid Network (LiN).
Ada problem besar yang saya amati dari LiN ini, yang diturunkan dari problem 2WP, yakni federation yang menguasai "vault" dari bitcoin yang disetorkan pengguna saat peg-in.
Federation punya kekuasaan untuk memindahkan BTC dari satu alamat ke alamat lain, selama mereka memenuhi k-of-n multisignature di mainnet BTC. Di sini, bila ada k anggota federation yang berbuat curang, maka BTC bisa hilang. Back sudah menyadari potensi masalah ini di papernya. Oleh karena itu, LiN barangkali hanya cocok untuk komunitas kecil.

Kemudian, adanya confidential transaction (CT), menurut intuisi saya, akan membuat sulitnya audit L-BTC terhadap BTC yang di-peg. Mengingat di dalam CT, jumlah koin terenkripsi, maka akan sulit membuktikan jumlah L-BTC beredar = jumlah BTC di-peg.

Dear cryptocurrency users,

I am a PhD researcher at Monash University, Australia. I am a part of the cybersecurity group of Faculty of Information Technology who are focusing on blockchain technology. Our interests lie in privacy-preserving cryptocurrencies and how cryptographic techniques are being implemented in those cryptocurrencies.

I am conducting a survey to better understand the users’ perspective towards Monero's privacy features. The purpose of the survey is to investigate how Monero is used and how the Monero users perceive the anonymity of Monero.

If you are a Monero user (owning Monero or having experience in using Monero), we invite you to respond to our survey. We do not record your IP address information, referrer, or any other information otherwise explicitly stated.

The survey will take up to 15 minutes to complete and is available through the following link: https://monash.az1.qualtrics.com/jfe/form/SV_egnHCGdgXMS6Kt7.

Our study has been approved by Monash University Human Research Ethics Committee (Project ID. 16933).

Thank you in advance for your help.

bitcointalk ada sejak era satoshi memperkenalkan bitcoin. topik-topik serius paling enak di-post di sini, apalagi yang berkaitan dengan teknis yang tidak ada di manapun, biasanya dapat jawabannya di sini.

saya malah setup website, twitter, facebook page tentang kriptologi (kriptologi.com) 
asal share info/teknologi yang bermanfaat oke2 aja kok. jangan share link afiliasi yang gak ada manfaatnya.

gak apa2. yang punya gak berkeberatan kok 

saya pelajar... s3. hehe.

your suggestion was awesome!

I managed to redeem the transaction (I created a new P2SH script without the push opcode).

https://blockchain.info/tx/4ba75dfe11988663cfcbbc8911eedee1f867d99fa744a6137e885315b3a073e1

the OP_CSV is simpler compared to OP_CLTV in my opinion, since we do not need to set the nLockTime and calculate a specific time in the future. All we need is just the nSequence with nSequence >= OP_CSV value and set the tx version to 2. Awesome! Thank you @piotr_n.

hello, it's been a while  

anyway, do you have any suggestions about this OP_CSV problem? if the push does not matter in OP_CSV as you said it only saves a byte per input. I already have set the version to 2, then what else, did I miss something?

Thank you for your reply. I have rechecked my script and it uses 0x01 0x0a instead of 0x5a.
Just to make it clear, according to Bitcoin Wiki (https://en.bitcoin.it/wiki/Script), does it mean if we need to push numbers from 1-16, we shall use OP_1 to OP_16?

Thank you for your reply.
I have tried to use version 2. I also have read the BIP and I assume that one only need to set the nSequence variable to be higher than the OP_CSV value, it means it has nothing to do with the nLockTime. All Failed.

Someone told me that this OP_CSV is not currently active in mainnet.

Dear all,

I am currently studying the OP_CHECKSEQUENCEVERIFY (OP_CSV) opcode and trying to create transactions manually. I have this construction

OP_IF
   2 [PUBKEY A] [PUBKEY B] 2 OP_CHECKMULTISIG
OP_ELSE
   [CSV VALUE] OP_NOP3 OP_DROP
   OP_DUP OP_HASH160 [PUBKEYHASH B] OP_EQUALVERIFY OP_CHECKSIG
OP_ENDIF

So far I have succeeded redeeming the P2SH tx above through the multisignature (the OP_IF.. block). But I have problems when redeeming the transaction through the OP_ELSE.. OP_ENDIF block which is when the OP_CSV is evaluated. I have set the [CSV VALUE] to 0x0a in hexadecimal (or 10 in decimal).

My current effort was to set the nSequence and the nLockTime variables to be more than the CSV value. I have created a raw tx to redeem the OP_CSV as follows

01000000010c3e18ff26e98ba39381c84d2fb9e8e198e63d0b3697f9bd57f63577c96da23f00000 000d5483045022100fc4f7bfa3c536e743b02af8b7de5d4052f43db54f59692478b25c585b9df21 1a02203cfcfc0ed618fae6aa49b11e803ec4e5654551fb52fe2d026929f4a307fe2ef0012103d7c 6052544bc42eb2bc0d27c884016adb933f15576a1a2d21cd4dd0f2de0c37d004c67635221025e37 e03703f001de34123b513beaf0e4044a2dd39a1dd92ec1706f184920031a2103d7c6052544bc42e b2bc0d27c884016adb933f15576a1a2d21cd4dd0f2de0c37d52ae67010ab27576a914937fe2ee82 229d282edec2606c70e755875334c088ac680f0000000130750000000000001976a914937fe2ee8 2229d282edec2606c70e755875334c088ac0f000000

In the raw tx, I have set the nSequence to 15 and nLockTime to 15 (I know this is not a good idea, but I'm desperate).

The raw tx itself was rejected in many pushtx services, except the blockcypher, although it has not been confirmed to the blockchain.
https://live.blockcypher.com/btc/tx/bcfbb172403ba73643ae02d40cac1332b75173d9726917dd8263a15ce365c012/

Please let me know if you have any suggestions. Thank you.

That's why I quitted using testnet (and people do not stop asking me why I do the tests in mainnet).
I emailed Josh Cincinnati from blockcypher.com and he said it would be better to run the test in our own testnet, or we can also use their testnet.

https://medium.com/blockcypher-blog/testnet-is-not-for-testing-5afa78b1394

block halving itu tentang pemotongan "upah" para penambang bitcoin. jadi ga ada hubungannya dengan jumlah BTC yang beredar. sekarang ini upahnya masih 25BTC perblok, nanti sehabis block halving akan jadi 12.5BTC upahnya per blok.

I crafted a tx pair similar to yours (same cltv block and same locktime) in testnet, I think it is correct but it won't be sent to the network.
This is the rawtx

I wonder if the CLTV is not deployed in testnet yet

Block halving sudah pernah terjadi. Ingat kan, awal mula reward per blok itu 50BTC, sekarang sudah 25BTC. Block halving berarti akan jadi 12.5BTC. Tidak ada hubungannya dengan jumlah bitcoin yang sudah beredar.

I don't really understand the question. Do you mean you cannot produce a valid signature by using your tool? I checked the rawtx you created and indeed the problem is within the signature. webbtc verifies this as well.

Are you trying to redeem the CLTV block? BX decodes the tx as follows.


I wonder why there is a zero there.

Last time I checked, it is still buggy. This one https://webbtc.com/script is one of the best so far, despite it does not work lately.

Hi, many thanks for the clue. I managed to construct the following structure

The structure probably is the first few steps of Gmaxwell's Coinswap. I am not sure whether this can be called as atomic. Basically the tx can be redemed by 3 different ways:
- secret value + sig2
- sig1 + pubkey1 after certain CLTV
- sig1 + sig2 (in 2-of-2 multisig)

I was trying to add another branch of OP_ELSE to mimic Gmaxwell's CoinSwap but I don't really know how to skip the previous OP_ELSE and run the next OP_ELSE. Do you know how to do it?