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1  Bitcoin / Bitcoin Technical Support / [POLL] How long to sync on an initial core install on: January 09, 2018, 02:30:13 AM
Performing a fresh install on a very wimpy computer.  It's syncing now and will look to take between 1-2 weeks to sync.  I know this is way outside the bell curve and I'm far far below the minimum install requirements, so... Wanted to know how long a propper install takes to perform.  I'll give the form for the reply data, if anyone cares to fill it out:

Rules: Fresh installs with no pre seeded block data or levelDB data

  • Duration: Number of hours it took to sync.
  • Date: When was the sync started?
  • Version: Bitcoind or Bitcoin-QT version?
  • Headless: Running Bitcoind or Bitcoin-QT?
  • Pruning: Pruning enabled?  If so, what argument was given?
  • dbcache: dbcache limit enabled?  If so, what argument was given?
  • maxmempool: maxmempool limit enabled?  If so, what argument was given?
  • bandwidth: What network bandwidth was the system capable of?
  • DiskIO: What disk bandwidth was the system capable of?
  • CPU: What CPU type / count?
  • Memory: How much memory (RAM) was installed?
  • OS: What OS was installed?

Here's my my config (I know... its wimpy and well below the minimum requirements)

  • Duration: 336 hours (projected), aka: 14 days, aka: 2 weeks
  • Date: Jan-6 2018
  • Version: v0.15.1
  • Headless: Yes, bitcoind
  • Pruning: -prune=20480
  • dbcache: -dbcache=155
  • maxmempool: -maxmempool=5
  • bandwidth: 500 Mbit/s
  • DiskIO: 100 MB/s
  • CPU: 0.5 vCPU, GCE f1-micro VM with 0.5 vCPU (shared CPU)
  • Memory: 0.6 GB
  • OS: Unbuntu 17.10 (artful)
2  Bitcoin / Bitcoin Discussion / How many TXNs in the mempool could be bundled. on: January 07, 2018, 10:55:49 PM
I know the subj is confusing... read on...  I gather fees are a basic supply/demand equation.  Supply is the space in the block.  Supply can be increased by using Segwit and bundling transactions.  I'll leave LN for now because as of today (Jan2018) there are very few wallets that support it.  Now, I may be able to bundle some of my TXNs buy leaving my coins on my phone longer than I want so that when I move them to cold storage I do it monthly instead of weekly.  But I think the biggest opportunity for bundling would be the exchanges.  Specifically on outbound TXNs.  All the exchange TXNs I've done are the typical <5 input and <5 output TXNs.  I'm certain this could be optimized, but since some of those fees are paid by the user, the exchanges incentives are one degree removed, slowing adoption.

So.. If my suspicion is correct that a significant number of TXNs are unbundled exchange TXNs, has anyone put some serious study behind it.  Obviously we are talking millions in fees here, so that is a lot of money to leave on the table.  It would seem that if you knew an exchanges hot-wallet, thier mining pool and some possible other tells, it would be possible to build a model where there is some statistical confidance that TXN y belongs to exchange x.  For the rEDITORs out there, I did say statistical as in less than 100% and more than 0%.  Not certainty.

If I'm still on the tracks, I'd be curious what fees would look like in this utopian world (even without LN) where we do effectively the same volume, but all exchanges use segwit (from addr) and their TXNs are bundled.  Bundles could be every hour (less optimized), or every day (most optimized).

TLDR: Fees would be negligible if exchanges bundled and used segwit.  It would drop fees by {TBD}%
3  Bitcoin / Hardware wallets / Import Android wallet to Trezor [SOLVED] on: December 23, 2017, 04:11:55 AM
Anyone try this.... thought it might be fun.

So I saw in decrypt threads that someone was able to extract the BIP32 key and derivation path.  Since both of these can be loaded into a Trezor, has anyone tried this to see if they get the proper key data?  I plan to... but not till next year.  Too much to do right now.  Maybe we can get a thread started to try to figure out the gotchas before I dig to deep.

4  Bitcoin / Development & Technical Discussion / Why are some miners charitable with low fee TXNs? on: December 13, 2017, 03:34:23 PM
UPDATE: These are all CPFP... mystery solved.


There has recently been a number of very good analysis tools / sites related to fee calculation based on mempool fee distribution.  I began to get more interested in fee distribution on confirmed blocks instead.  I believe both pursuits are important.  One gives info on what the competition is while the other gives info on what the last selection process was.  What I've found is that all blocks seem to include... for lack of a better term... charitable transactions.  I'm trying to understand why.  If there is an abundance of fair fee transactions in the mempool, why would a miner include anything else.  The best WAG I can come up with, are the following:

  • Off-book incentive - Perhaps the miners have an off-book incentive to include some transactions that further their business.  Some payment to another pool or their utility company or whatever.  Perhaps the transaction is low-priority as far as the miners are concerned, so they include some fee in case some other miner finds it, but really they are just waiting to pick up those transactions themselves.
  • Too busy to care - Perhaps the compute cost to actually filter out the transactions is higher than the benefit of excluding them.  To me this is the most likely.  There are good ways to do a sloppy sort that would get a selection mostly sorted, but not entirely.  I'd imagine a bubble-sort continually running on the mempool, but blocks periodically getting cut before the sort is complete.
  • Child-pays-for-parent - Perhaps these low fee transactions are CPFP transactions, and there is a high-fee child somewhere in the block.  I'll need to modify my block-walker to try to flesh this-possibility out.
  • A perfect fit - Perhaps the size of the transaction is perfect to allow the block to be at maximum capacity.  For example, if there were 191 bytes space left in the block, it is obviously more profitable to include a low-fee 191 byte transaction, than to just leave that space blank.
  • Something I don't know - I accounted for SegWit, and admittedly did not account for CPFP.  Perhaps there is another part of the protocol that makes these TXNs profitable that I failed to consider

5  Other / Meta / @Mods, can you help me move a thread to the technical board? on: November 20, 2017, 04:56:41 PM
It's currently in the Bitcon General board, but perhaps it's a technical question after all.

Maybe it's simply been talked to death elsewhere and I just failed to find the thread.

6  Bitcoin / Development & Technical Discussion / SegWit transaction preference on: November 19, 2017, 07:47:55 PM
Could anyone ELI5 how SegWit transactions factor into SegWit blocks?  I get how SegWit blocks segregate the witness data and how that is advantageous because it increase block size for the client and increases transaction count (and likely reward) for the miners, but how does all this tie into SegWit addresses?

  • Do all outputs of a transaction need to have segwit outputs for them to have their witness data segregated?
  • Do all inputs and outputs of a transaction need to have SegWit adresses for them to have their witness data segregated?
  • Can a transaction with mixed with some SegWit inputs and some SegWit outputs have their witness data segregated?
  • Is it believed that, statistically, this profiling by miners will cause SegWit capable transactions to cost less satoshi/byte than non SegWit transactions?

7  Bitcoin / Bitcoin Technical Support / Extracting wallet.dat keys from ancient bitcoin-qt client without network. on: November 19, 2017, 06:12:28 AM
I have an old client that was running on a very old computer.  I have all the wallet passphrases and everything is in good shape, but there is literally *NO* way this client can ever catch up on my data plan and my vintage HD.

I have some lint in the wallets.  Nothing worth caring about till now.  Kinda like shale, the price is high enough for me to go through the work to extract the lint.  Last time I tried this, I concluded that I needed to sync with the blockchain, tried for a week and just gave up.  Maybe my assumptions were wrong.

Is there a way (maybe through bitcoind.exe) to start the client and *NOT* sync the blockchain.  Just get to a console where I can dump *ALL* private keys in the keybag.  I realize it will be a few hundred, but like I said... at this point it's worth the hassle.

If not... can the wallet.dat be decrypted with openssl and hexdumped to find the offset of the keybag?

8  Alternate cryptocurrencies / Service Discussion (Altcoins) / Why the Tether / Bitfinex thing will be OK? on: November 18, 2017, 10:17:25 PM
Crosspost from reddit.

I've seen a large volume of articles talking about Bitfinex and Tether being a time bomb in the bitcoin market.  There are many posts so I won't rehash them.

My question is.. what is the Affirmative argument.  Points I have on the other side (bullish on bitcoin) are as follows:

  • Bitfinex + Tether are < 30% of the volume... much less than MtGox
  • Tethers daily volume is $590 Mil -vs- Bitcoin volume of $3803 Mil... So only 15% of bitcoin trades.
  • might be telling the truth and actually have $590 Mil in their reserves account in HK.
  • might be taking huge infusions of cash from other exchanges like Kraken.
  • The spike in Tether releases in market dips could be institutional customers ($10 Mil +) grabbing Tether to buy the dip.

Again... I'm just trying to get the other side of the argument.

Disclaimer: I hold bitcoin.
9  Other / Meta / Name Change Notification on: July 26, 2015, 01:02:17 AM
   I am planning on changing my userid.  Seeing that I don't have sufficient rank to perform a name change, I will likely just create a new account and start to post from it.  I realize that this isn't strictly against forum rules, but wanted to post this thread so that my intent is clearly stated and not seen with suspicion.

If I receive no advise against this over the weekend, I will post the new userid here.


10  Bitcoin / Development & Technical Discussion / [HowTo] Use PyBitcoinTools to make CPFP transaction with tip to bounty on: July 17, 2015, 04:45:09 PM
I've been playing with Vitalik's Bitcoin Python library.  It is fantastic and I highly recommend it.

Here's a small utility script I wrote that uses it to create CPFP transactions for users needing rescue.
11  Bitcoin / Development & Technical Discussion / Bounty for CPFP Enabled Wallet on: July 15, 2015, 08:12:27 AM
CPFP (Child Pays for Parent) Bounty

Anyone who can put a CPFP transaction creation feature into any wallet featured on the bitcoin homepage can claim this bounty.  

I outlined the basic idea of the bounty in this BIP proposal before I was educated on CPFP.

To claim the bounty / pizza you will need to convince the following holders of the multisig

  • Must be a wallet featured on the bitcoin homepage
  • Must be either accepted into primary build branch of (1), or available in an official release / beta / dev build of (1)

12  Bitcoin / Bitcoin Discussion / CPFP Enabled Wallet Community Bounty Campain on: July 15, 2015, 07:46:21 AM
CPFP (Child Pays for Parent) Bounty donation address

Note, this is a multisig address, I can't spend the funds.

I'm starting a bounty campaign to try to raise funds to get wallets that can retrieve unconfirmed transactions from the mempool.  The current spam attach is still causing a number of users to have transactions drown in the mempool.  Setting proper transaction fees will unquestionably fix any future transactions that they make, but general users lack the ability to do anything about the transactions they have already sent.

How CPFP (Child Pays For Parent's fee) works
I tried to explain it here before I knew what it was.

Transactions in bitcoin are actually chained together.  Each transaction has an input and output.  New input links to old output.  So lets call the transaction you want to rescue the "parent".  To employ a CPFP rescue attempt, we create a new transaction ("child") that spends (links to) the parents outputs.  This new child transaction will be coded with generous fees.  When a CPFP miner like Eligius sees the pair of transactions, they are scooped up and included in the block.  So adding the high fee "child" transaction pulls the "parent" out of the mempool.

What do Wallets Need to Do?
Most wallet software is in a perfect position to see what unconfirmed transactions in the mempool are related to the user.  It would be technically straight forward for the wallet to alert users that their unconfirmed transactions are being passed over.  More over, it they could provide a "Rescue Transaction" or "Deploy Lifegarud" button.  In either case, the wallet would examine the drowning transaction (incoming or outgoing) and chain a new high-fee transaction to it.

Does it really work?
Yes, I pulled a transaction out of the mempool after 188 hours (8 days).  The whole history is viewable on TradeBlock since they are less agressive about purging their mempool.

Here is my original parent transaction that I sent:
Parent: 358762a9f2fcbd141eae29a8df82a822930428605f4a033e53baaaa377d3df4a
Here is the "Lifegaurd" I sent in directly to Eligius:
Child: 8ef3eec72db231feedc1d5e1e5b24f36e290c94344f86822202378320f8380d9

What miners process CPFP?
Currently only Eligius processes these transactions.  They make up about 5% of the current miners pool.  They usually win about 5-6 blocks a day, so it won't be immediate, but if someone has been waiting 12 hours, it will sure be a relief.

Is CPFP the only option?
No, there is RBF (Replace by Fee) that does the same thing, but as a kind of sanctioned double-spend.  There is already a $1000 bounty out for the first developer to get that one to stick.

Volunteer Lifeguard Service
If you just need your transaction out of hock and don't care about the long view... I have set up a non-profit transaction rescue service that will also serve to fund the campain.

13  Bitcoin / Bitcoin Discussion / Anyone understand bitcoin-core "accounts" language? on: July 15, 2015, 05:11:09 AM
I've been trying to study the RPC and there are times where "accounts" is used and others where "address" is used.  There is also a command called "move" which moves balances from one account to another.  My accounts have a negative balance (neat trick).

So can someone explain what an account is?

How are accounts and change addresses correlated?

How do I get a negative balance in an account?

How do I merge accounts?
14  Economy / Services / [Unconfirmed TXs] non-profit transaction rescue service (starting at 0.003 BTC) on: July 14, 2015, 11:42:34 PM
I'm offering this service to pay for a developers bounty on CPFP (not for my own profit).

I have seen a number of threads from people complaining about unconfirmed transactions.  There is a way to pull these transactions out of the mempool with a degree of technical skill.  I'm willing to put my effort to work to craft the proper transaction to pull these unconfirmed transactions out of the mempool.  The cost for this is based on the unconfirmed transaction size, but will start at 3 mBTC (0.003 BTC).  All proceeds will be paid into the bounty to have CPFP integrated into one of the major wallets.  Basic process follows.

Users of this service will be required to sign the provided transaction.  On some wallet applications this is strait forward, on other wallet applications it is not.  I'll help out however I can, but I will not sign the CPFP transaction, nor will I accept any private keys to do this.  Please keep your private keys private.

Minimum Donation Schedule
<1 KB - 5 KB
3 mBTC
>5 KB - 10 KB
4 mBTC
>10 KB - 15 KB
5 mBTC

Turn around time
About what you would expect from a volunteer.  I should be making transactions once a day, then send them back to you to sign.  I'll probably code the transactions between 01:00 UTC and 05:00 UTC, but no guarantees.  Once you sign the transaction you (or I) can submit it to the Eligius pool who will be doing the block.  They usually get about one block every 5 hours.

Contribute to the CPFP bounty anyway
If you would just like to see some client wallet implement a "Rescue Transaction" button using CPFP, feel free to the CPFP address.  Every mBTC helps...

What is Child Pays for Parent (CPFP)
I tried to explain it here before I knew what it was.

Transactions in bitcoin are actually chained together.  Each transaction has an input and output.  New input links to old output.  So lets call the transaction you want to rescue the "parent".  To employ a CPFP rescue attempt, we create a new transaction ("child") that spends (links to) the parents outputs.  This new child transaction will be coded with generous fees.  When a CPFP miner like Eligius sees the pair of transactions, they are scooped up and included in the block.  So adding the high fee "child" transaction pulls the "parent" out of the mempool.

Sign me up!!
If have a transaction that is stuck that you want to rescue, here is how you proceed.
  • Post to this thread that you need a rescue.
  • Provide your transaction ID (either in your post, or in a PM to me)
  • Declare how much you want to contribute to the CPFP bounty (either in your post or via PM)
  • I'll take the transaction info and generated a raw transaction and send it to you via PM
  • Inspect the transaction with the transaction decoder to ensure your comfort
  • Verify that you see your address, the donation address, and the TX you are rescuing in the decode.
  • Sign the transaction with your bitcoin client, or any other method you choose
  • Either submit the transaction yourself, or PM me and I'll send it for you

What is a raw transaction, and how do I sign it?
I'll post a HowTo below to discuss how to sign raw transactions on various clients.

Is this a scam?
No... the "rescue transaction" will have the donation in it.  Your donation only goes through if the rescue works.  The donation address is also a 2-3 multisig address, so I can't unlock the funds myself.

Wait... where's the donation address?
I'm gathering some info to generate it shortly... stay tuned... for now just let me know if you need help, I'll work the rest out with you shortly.
15  Other / Meta / [REQ] Admin / Staff / Mod Escrow to help with CPFP bounty. on: July 14, 2015, 08:54:54 PM
Apologies on the large distro, but I would like to request the help of a well respected person on this forum.

My request for CPFP client-side controls:

I've been trying to advocate CPFP to transactions out of the mempool.  I have a working script and would like to volunteer my time as a "Transaction Lifeguard" fishing transactions out of the mempool.  It is fairly easy, and I fished one of my transactions out after 8 days.  Since everyone needs this, I was going to do it for a small fee (3 mBTC) that would be paid to an address.  That address would hold the funds to pay a wallet developer to add CPFP to a mainstream wallet.  Since me controlling the wallet would sound like a complete scam, I wanted to offer to create a 2-of-2 multisig that a respected entity on the forum shared.  My idea goes something like this.

  • Create multi-sig addr { $myProfileBTCAddr, $yourProfileBTCAddr } -> $bountyAddr
  • Post a thread (in Bitcoin) advertising the CPFP bounty campaign and $bountyAddr
  • Post a thread (in MarketPlace) offering transaction lifeguard services
  • People requesting rescue on their SPEND TX would send( $thierTransID, $addrOfIntendedTxRecpt, $mBTCwillingToPay )
  • People requesting rescue on their RECIEVING TX would send ( $thierTransID, $thierRecvAddr, $mBTCwillingToPay )
  • From (4,5), determine the address the requester owns in the unspent TX outputs ( $unConfTxOutput )
  • Create a high-fee CPFP transaction ( $unConfTxOutput -> { $unConfTxOutput, $bountyAddr } )
  • Mail / Post the TX hex back to the requester for them to sign in mycelium or bitcoin-qt, or whatever
  • Help requester submit the CPFP TX to Eligius for processing

Each transaction rescued will add 3 mBTC ($1) or more to the $bountyAddr and entice more people to submit Pull requests to claim it.

Obviously I need an address to include in step (1), and I don't how easy step (8) will be for the average user.  Also, don't know of 3 mBTC is the right price, or if this whole idea has gone sideways.

I can of course proceed on my own, but I seriously doubt if people would trust me to give the money to the devs and not just run off with it.


EDIT: Proof-of-Concept that CPFP works.
16  Bitcoin / Development & Technical Discussion / Bitcoin RPC based CPFP script on: July 14, 2015, 04:47:37 PM
Still pretty rough, but here's a script to create a CPFP transaction from and unconfirmed in your wallet.

This will also give you the raw HEX transaction data to submit to Eligius

I found a Eligius submit URL here:

I recommend you get your fee schedule from here: (or the estimatefee RPC)

Warning.. I did tweak bitcoinrpc.authproxy to support use simplejson instead of json.  I'll post a pull for that later.
17  Bitcoin / Bitcoin Technical Support / Any safe way to config RPC when running on TOR? on: July 12, 2015, 04:54:36 PM
Background, I'm running a full node, but my Orwellian ISP bans peer to peer (even calls it out in the TOS), they have even warned me when they see ports open through my NAT.  So to counter my ISP, I'm running bitcoin on TOR.  This violates TOS, but they haven't detected my TOR config since I use bridges.  I'm configured with -onlynet=onion so a lot of the exit-node threats would be neutralized.

Running bitcoin on TOR works great... but... this has the side effect of binding EXTERNAL traffic to  My fear is, that opening up RPC requests with -rpcbind= would open me up to the world.  Similar to -rpcbind=* (<== bad!!!).

Now on the the one safeguard I have is that TOR only binds specified ports to through their hidden services config.

So if I configure TOR to only bind to, then go ahead and open up (locally, not TOR), should I be safe, or would I be foolhardy.  This is my hot wallet I'm talking about.

BTW, the reason I'm not binding RPC to a fake addr like is that I need RPC for walletpassphrase commands.  I never felt good about issuing those through bitcoin-cli since the argument list is in the clear and viewable by any process or service on my box.

PS.. realize this is kind of a TOR specific question, so I will likely cross post to /r/TOR
18  Economy / Service Discussion / Any blockchain browsers allow bitcoind RPC calls in thier API? on: July 12, 2015, 07:17:52 AM
I thought I saw one of the many blockchain browsers that allowed some of the bitcoind RPC commands like "getinfo" or "getmempoolinfo" through.  Basically a public facing bitcoind server.  I'm sure that under the covers the RPC calls are proxied and throttled, but I could have sworn one of the big providers was offering this.  Don't think it was, but someone.

Any thoughts?

My goal, if you ask, is to work a python script using "estimatefee" and "estimatepriority" to provide some feedback to current mempool transactions.
19  Other / Politics & Society / BTC Spammed, then CNY halts trades, then NYSE halts, now lost SSL on: July 08, 2015, 07:54:33 PM
Things are looking kinda spooky.


Should I look for black helicopters and put on my tinfoil hat?
20  Bitcoin / Bitcoin Discussion / [1st Conf after 188 hrs] The unconfirmed TX highscore! [week of Jul 5th] on: July 07, 2015, 09:36:52 PM
This thread will log TX time high score.

First off... I fully understand and acknowledge that being generous with tx fees will greatly reduce these wait times.  No "To fix it just..." posts please

Secondly... don't hand code any low fee transactions, that is bad.  Just use a normal bitcoin client, then log your transaction time.  Previously the highest I saw for something that wasn't tainted was 10 hours.

  • Don't hand code low fee transactions, just the defaults please.
  • State the bitcoin client you used to send your transaction.
  • Post how long it has waited in the mempool at your time of posting.
  • Your TX URL @ since they list mempool times for unconfirmed txs.
  • your TX URL @ since they list mempool times for confirmed txs.
  • Post the transaction URL to claim victory.
  • Optional: Link imgur thumbnail (see here) showing txid and wait time.

Quote from: __Me giving You an example__
Client: Bitcoin-Qt XT v0.10.2
Wait time: 17 hours edit: got first confirmation after 188 hrs.
TradeBlock URL:
blockinfo URL:

To the winner goes the spoils....  The winner will receive some, or none, of the following:
  • Glory and forum fame
  • Much sympathy from the readers
  • Many cry emojis  Cry Cry

Final Standings
1st d4n13
2nd lahm-44

Edit: I finally pulled the TX out of the mempool after 188 hrs with a CPFP transaction.
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