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October 03, 2023, 04:58:29 PM *
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1  Bitcoin / Electrum / RBF adjust fee, choose adjusted output? on: March 18, 2023, 08:58:34 PM
I created a RBF transaction recently that has a single input and two outputs.
Output A sends to somewhere that I'd like to transfer some funds.
Output B is the change back to my Electrum wallet.

However, I was feeling patient (and greedy), so I adjusted the fee to be especially low.

Now that some time has passed without confirmation yet, I'm becoming impatient and have decided I don't want to wait quite so long anymore. I want to increase the fee paid on the transaction.

However, if possible, I don't want to add any additional inputs to the transaction, nor do I want to alter the amount in Output B being sent to the change address.  Instead, I'd like to reduce the value of Output A, so that the additional fees come from the funds that are being transferred.

Is this possible?  And if it is, what are the steps in Electrum 4.3.4 to accomplish this?
2  Bitcoin / Development & Technical Discussion / How to get <target> values for a block? on: December 17, 2022, 09:43:33 AM
User HoBzY posted a question in this sub-forum, but it seems that the thread got locked (maybe on purpose, maybe on accident).
Here's a link to the original question:

How do you get 422681968 nbits out of 86564599.52 complexity?

Or how do you get the target value in general?

I sent him the following message, but I figured I'd include it here as well so there's an opportunity for others to correct me if I made a mistake in any of the math or formulas (it is almost 4am here and I haven't slept yet, so mistakes are vERY possible):

You provided nbits = 422681968
If you convert that integer value to hex, you get the 4 bytes (32 bits) that nbits is made up of:
422681968 = hex value 0x19319D70

Split the first byte off of nbits to get hex value 0x19 leaving behind the remaining 3 bytes of 0x319D70
These are the two pieces that are used to calculate the target hash value and the difficulty using this formula:
TARGET = 0x319D70 * 2(8(0x19 - 3))

To make the math a bit easier to understand, we can convert those hex values back to integers for the purposes of this discussion:
= 3251568 * 2(8(25-3))
= 3251568 * 2(8(22))
= 3251568 * 2176
= 3251568 * 95780971304118053647396689196894323976171195136475136
TARGET = 311438341301388531462158357898567283222551020627518185013248

Convert this value back to hex to get the hash value that the block hash is compared to:
TARGET = 0x00000000000000319D7000000000000000000000000000000000000000000000

You may notice that hex value of TARGET is 0x319D70 shifted to the left until the 31 is in the 25'th (0x19) byte from the right. That's what that formula above does. It takes the last 3 bytes (6 characters) from nbits, and shifts them to the left until the first byte of that block of 3 bytes is exactly the number of bytes from the right that is specified by the first byte of nbits.

Now that you have the TARGET, the DIFFICULTY is just:

Let's convert the formula above into integers to make the math easier to follow:
(65535 * 2208)/TARGET

We have the integer value of TARGET above so:
(65535 * 2208)/311438341301388531462158357898567283222551020627518185013248
= 86564599.52 = DIFFICULTY

You didn't ask for it, but the calculation of the expected hash rate for a given difficulty is closely related, so I figured I'd share it.

The average number of hashes needed to find an acceptable hash at a given difficulty can be calculated as:
DIFFICULTY * 2256 / (0xFFFF * 2208)

Since the DIFFICULTY on the previous example was:

The average number of hashes that need to be calculated per block is:
= 86564599.52 * 2256 / (0xFFFF * 2208)
= 86564599.52 * 2256 / (65535 * 2208)
= 371797797113897361

Since blocks are intended to occur on average every 10 minutes (and there are 600 seconds in 10 minutes), this means that a DIFFICULTY of 86564599.52 would be set when the global average hash rate is:
371797797113897361 total hashes / 600 seconds = 619662995189828 hashes per second.

That's about 619.663 Thash/sec
3  Bitcoin / Bitcoin Discussion / DannyHamilton invited to participate in an amateur podcast on: June 07, 2022, 10:24:15 PM
Some friends of mine created their own podcast a few years ago. Earlier this year I was invited to participate in a cryptocurrency discussion for a few episodes.  If you're interested in listening, you can find the conversations here:

Boomer and Doomer: Conversations across generations

If you prefer not to click links or you don't like Spotify, you can search for their podcast on any of several major podcast outlets and then find the conversations using the titles I've posted above.
4  Other / Meta / How to find threads with pairs of users? on: January 12, 2022, 04:11:04 PM
Does anyone know of a way to find all threads on the forum where two specified users BOTH posted in the thread?

Like for example if I wanted to find all threads where franky1 and LoyceV BOTH have posts in the thread, or all threads where gmaxwell and myself BOTH have posts in the thread?

If I'm looking for pairs where neither user has a huge number of posts, I can probably just go to each of their profiles and capture the list of all threads from their "Show the last posts of this person." link, and then write a quick program to find threads that exist in both lists.  However, capturing the unique list of all threads for someone that has tens of thousands of posts might be a bit more effort.

Before I put a bunch of effort into writing something that will scrape all that data from the forum and that will compare the results of that data capture, I figured I'd check here to see if someone knows of a web service that can already do this for me, or some open-source code I can pull down and use that already does this??

I'll wait a few days for a response before I start trying to write anything, thanks.
5  Bitcoin / Development & Technical Discussion / Quick question regarding Generation Transaction on: December 28, 2021, 04:35:52 PM
I'm pretty sure I recall there being a requirement added for a miner (or solo or pool) to put something specific in the input portion of the generation transaction to prevent an issue that came up where two different generation transactions in two different block heights both used the same output script and therefore had identical transaction hashes.  Unfortunately, I can't seem to remember exactly what it is that is supposed to be added to make the transaction unique, and a quick search on Google isn't turning it up.

Am I remembering incorrectly?  Or can someone tell me what it is that's supposed to be added?
6  Bitcoin / Hardware / Want to purchase Bitcoin mining ASIC. on: December 05, 2021, 05:15:36 PM
I've been around BitcoinTalk for a long time, but I'm very new to the mining section of this forum. I apologize if this post belongs in the Marketplace section of the forum and not in the Mining Hardware section.  Just let me know and I'll move it.

I've got this idea about using the waste heat from mining equipment to heat my garage here in the cold northern Illinois winter. Since the main purpose of the equipment is to heat the garage, the equipment doesn't even need to turn a profit. It just needs the NET cost of operation to be cheaper than running a heater in the same space.

As such, what I'm looking for is the highest watts per purchase cost that I can get.

If you've got some used equipment to sell that is no longer profitable to run, please contact me. The higher watts the better.

Obviously, I'll need a PSU to run the equipment as well. I'm in the U.S. and I currently have access to both 120V 15A (NEMA 5-15R) and 240v 50A (NEMA 14-50) in my garage.

Initially, I'm wanting to spend less than $500 all together for all the necessary equipment. If I'm happy with the results, I may spend more in the future.
7  Bitcoin / Mining / Help with revenue calculations on: August 24, 2021, 04:48:57 AM
While Iíve been active here at bitcointalk for nearly a decade, Iíve avoided getting involved in mining.  Itís been my opinion that, given my local cost of electricity, the cheaper way for me to acquire bitcoins is to buy them, rather than mine them.  However, a few variables have changed recently, and Iím thinking about dipping my toe into the mining pool.  I know that, if Iím going to do this, Iíll need to acquire some sort of ASIC, and Iíll need to figure out how to get it set up.

Hereís the situationÖ

I now have an electric vehicle, and as such I now have 240 volt 60 amp circuit run to my garage.
Iíve recently insulated my garage to retain some heat.
I live in the Chicagoland area where outdoor winter temperatures regularly drop to -10 Celsius.
My garage doesnít currently have ANY heating service run to it.

My thought (hope?) is that I can set up an ASIC in my garage, and generate enough heat this winter to keep the temperature in the garage above 0 Celsius while paying for the cost of heating the garage via the BTC generated by the ASIC.  Essentially, the ASIC (hopefully) becomes a garage heater that pays for its own electricity. At the end of the winter, I'd sell the ASIC (assuming I was able to maintain at least break even on the electricity for the duration), so the total cost of heating the garage for the winter would just be the difference between the purchase price and sale price of the ASIC.

Iím trying to figure out how efficient (MHash per Joule) the ASIC needs to be to break even on the electricity used at current difficulty and bitcoin exchange rate. Iím not sure if Iíve got the maths correct, and I was hoping some experienced miners here could check my calculations and let me know if Iíve messed up somewhere.

Here are the values Iím using for my calculations:

- Local electricity cost = $0.13 / kWh
- Current BTC exchange rate: $50,000 / BTC
- Current Satoshis earned per ExaHash: 7668 sat/EHash

Using those numbers, I seem to have calculated that Iíll need an ASIC that generates at least 9,418 MHash/Joule to earn the $0.13 per kWh that Iíll need to break even.  Does that sound right?  Did I mess up the calculation somewhere?  If so, can you explain the correct calculation for me?

Once I understand the correct calculation, I'll set up a spreadsheet where I can regularly update the electric rate, exchange rate, MHash per Joule of the ASIC, and difficulty to determine if I'm still earning at least my cost. That way I can shut off (and sell?) the equipment when it is no longer breaking even, or just avoid buying the equipment at all if I'm not going to be able to break even from the start.

8  Bitcoin / Meetups / 2019 AWS re:Invent meetup on: November 18, 2019, 08:11:43 PM
I'll be attending AWS re:Invent in Las Vegas in 2 weeks.

Any other Bitcoin enthusiasts going to be in the Las Vegas area from Dec. 1 through Dec. 5?

If so, perhaps we can arrange to hang out together at a bar or restaurant or something?

Reply to this thread, or hit me up with a direct message if you prefer not to publicly announce your interest.

Additionally, if you prefer that your interest in attending be kept especially private you can encrypt your direct message communications with my public key (see below). Provide your own public key and I'll send you an email address where we can continue the conversation off-site.

Version: SKS 1.1.6
Comment: Hostname:

9  Economy / Services / [Hiring] AWS Lambda JavaScript Video Manipulation on: October 04, 2019, 07:38:39 PM
I havenít been here in a while, but there was once a time when it was possible to find programmers here that would be willing to take on a small project for a small amount of bitcoin.  Iím hoping that is still true.

Note: I am a skilled and experienced developer. I WILL be able to read your code, and I WILL know if it is doing what it should and ONLY what it should. Do not waste your time trying to get some malware or backdoor past me. I could write this myself, but it would be tedious, and I'd rather just pay someone a small amount to handle it.

Please send bids via private message.

If you have any questions, you can post them to this thread or send them via private message if you prefer not to reveal your userID to everyone else.  Any questions received via private message will be posted by me, without your userID, to this thread along with the answer.

The project will be running in an AWS (Amazon Web Services) environment. MP4 video files will be dropped off as objects in an AWS S3 bucket. Each video file will be up to 60 seconds long.

I intend to trigger an AWS Lambda function with the S3 PUT event.

On request, I can provide a representative sample video file for the purposes of estimating the work involved.

My preference is that the Lambda function is written in JavaScript, and that it not use an excessive amount of imported libraries. However, "aws-sdk", ďlodash", and ďmoment" are all acceptable.  If you intend to use some other programming language or to import any other libraries, please list them when you provide your bid. I understand that you will probably have a preferred video manipulation library that you will want to use. If I decide that I don't trust any of your chosen libraries, then I will disregard your bid. Therefore, it is recommended to stick to well-known and widely used libraries.

I am requesting that code be written for the Lambda to accomplish the following:

Anytime the filename (S3 object key) ends with any of the following: ď*-right_repeater.mp4Ē, ď*-left_repeater.mp4Ē, or ď*-back.mp4Ē the video will be mirrored (flipped left & right) and written to a new AWS S3 bucket name, which will be provided as an environment variable ďOUT_BUCKET", using the corresponding filename (object key) ď*-right_repeater-mirror.mp4, ď*-left_repeater-mirror.mp4Ē, ď*-back-mirror.mp4Ē. Anytime the filename (S3 object key) ends with anything else, the video will simply be copied as-is to the same new AWS S3 bucket name without modification to the video data or the filename (object key).

The winning bidder is to provide the code for the Lambda function in a zip file ready to be uploaded to the AWS Lambda function

If you are bidding on this work, please provide the following:
1. Programming language you will be using (if not JavaScript)
2. Libraries you will be using
3. Cost of job (in BTC)
4. Estimated delivery date

Iíll leave this request open until Oct 12 at noon UTC.  Any bid that comes in after the deadline will be disregarded. I will send a message to the winning bidder before Oct 13 at noon UTC to make arrangements for delivery of code and Bitcoin. Full payment will be made within 1 hour of verifying that the code works as requested. I will test the code within 72 hours of receiving it.

If this project goes well, I will have a few more video manipulation code requests over the next 2 months, and I may also decide to pay someone to create a small website for me as well.  These future requests will be open bidding, just like this current project, but preference will be given to bidders that have satisfactorily completed work for me in the past if their bid is within 5% of the cost and 10% of the duration of the leading competing bid.
10  Economy / Scam Accusations / Don't ask me to escrow account purchases on: March 05, 2018, 04:43:13 PM
I just received the following  message:

Hello, looking to buy hero member for signature campaign, could you please kindly help me with escrow? I would like to pay in etherum.
Thank you.
Best Regards.
11  Economy / Reputation / Since I was asked about it on: February 28, 2018, 03:31:01 PM
I wasn't going to bother with a thread about this, but I was asked here:

Danny you saw this discussion upthread, right?  It would seem topical for you to clarify your point of view about that recent discussion, no?

That was in reference to this exchange between JayJuanGee and Devawnm367:

Jayjuan i got negative trust for asking for merit... i have to google everything i googled howto gain merit, and a hero rank on the forum said i have to make quality posts, then went on to say even with 100 quality posts i may not get any, because they are so hard to come by people dont want to give them out, and then he ended it with the best way to get merit and (the quickest) is just ask... im only asking you because you are legend rank... is there anyway i can redeem myself and fix it im not trying to have a neg trust, simply followed what higher ranking of official said for me to do... please dont neg trust only want to know how i can fix it.... or what is the consequences because i got neg trust and reported.... and how can i fix it thanks
Anyone can answer this question, and it does not need to be me.

Surely, I don't know the whole story of your situation, and maybe the whole story does not matter too much because I can gather a certain amount of information merely by looking at some of your post history, your trust rating and your so far received merits.   

The truth of the matter seems to be that you have a lot of shitty posts, and some of your posts seem to be excessively obsessed with merit and NOT even expressing your ideas very clearly.  Furthermore, you received 10 merits for a largely nonsensical thread that you had started, and you received those 10 merits on February 26, so I do not understand why you would need to be so obsessed with merit in the short term because, with those 10 merits that you already received, you have enough merits to rank up to member status, and you still have another 3 months (approximately) before you would even be eligible to rank up to full member, which requires 100 merits, as you likely know.    Anyhow, DannyHamilton negative trusted you on February 26.

If you really are serious about attempting to earn merit and attempting to get your negative trust removed, then you would likely need to work pretty hard to accomplish such.  It is not an impossible task, but it just seems to me that your whole approach, so far, has been a bit wacky with a lot of shitty posts. 

To me, your posts are so shitty that you would likely need to engage in some efforts to improve the quality of your posts and for several months.  Also, you should probably remove your negative trust of DannyHamilton (which seems to have been a retaliatory response from you towards him).  Perhaps after you post quality posts for a few months, then you might want to PM DannyHamilton and ask him if he would be willing to remove your negative trust or if he has some conditions that he would like you to meet before he removes your negative trust.  In the end, your negative trust is not going to stop you from participating in this forum - although it may prevent you from engaging in some signature campaigns, and if engaging in a signature campaign is your main goal, then it could take some time to resolve your matter and with some efforts on your side to consider ways to post quality rather than quantity. 

By the way, I am giving you a general suggestion, and certainly I don't know whether DannyHamilton might NOT be willing to remove negative trust from you, but surely it seems to me that if you engage in quality posting and improve your approach and discontinue soliciting merits, then it is possible that he may be willing to consider such a request to remove the negative trust that he gave you. 

NOTE: I would not suggest contacting DannyHamilton at all for several months, until after you have made some decent and materially demonstrable efforts to fix what he had negative trusted you for.  On the other hand, if DannyHamilton has a policy to never remove negative trust, then your account is going to be labelled with that negative trust from him hence forth.  That is not a death knell for your account, but would just be a factor and a part of the history of your account, that you could still improve with quality posts and discontinuing with asking for merits.

Below you can see how Devawnm367 responded...
12  Other / Meta / sMerit questions on: February 07, 2018, 04:03:43 PM
I've got two questions related to sMerits....

1. Is it possible to determine how many total sMerits are available on the forum at any given time (or on a given day)? Each month when the Merit Sources get their new sMerits there is a sudden increase in available sMerits.  Then as they get sent, and re-sent, and re-sent the forum total diminishes until there are nearly none left (or at least significantly less than at the beginning of the month), and we all have to wait for the sources to get some more.  I'm just curious if that quantity information is available, or if perhaps Theymos might publish a chart or CSV with something like daily weekly, or monthly totals.

2. When do the sources get more sMerits?  I know they get them "monthly", but is it on the first day of each calendar month? Every 4 weeks on Sunday? Every 30 days? Whenever Theymos gets around to hitting the "send source merits button"?
13  Other / Off-topic / How I handle Merit, and why on: January 25, 2018, 04:03:03 PM
EDIT: Some hints for those that feel their posts aren't getting recognized by me...
  • All of the following are generalizations, and ideals that I strive to.  However, I may choose at any time to behave differently than what is written here. If you feel that I've failed to give merit where I've said I would (or you feel that I've awarded merit where I said I wouldn't), get over it.  I'm human. I get tired, I get bored, I get annoyed, I have bad days, I feel generous, I have good days, I make mistakes, I change my mind. The fact that I've taken the time to write this policy does NOT mean that you can use this policy to control, manipulate, or change my behavior.
  • If you have ever had a signature ad, then I've almost certainly already clicked "ignore" on you before I've ever read even a single post of yours. I generally wont see your posts no matter how high quality they are unless I stumble across them some other way.  You'll significantly increase the chances of your posts being noticed if you have NEVER had an ad in your signature.
  • I don't care how good (or bad) your english or grammar is.  If you are sincerely trying to learn, or helping with CORRECT information where you can, then you deserve merit.
  • Posts that are completely unrelated to the thread discussion, WILL be reported to moderators, will result in me clicking "ignore" on you, and will probably result in your post being deleted by a moderator.
  • If it's obvious that you've posted in a thread without reading the earlier posts in that thread, your post WILL be reported to moderators, will result in me clicking "ignore" on you, and will probably result in your post being deleted by a moderator.
  • While appreciated, correcting my spelling or grammar mistakes will NOT earn you any merit (however, I'll likely review your posting history to see if you deserve merit for other posts).  Correcting any of my maths mistakes, or factual mistakes WILL earn you merit.
  • I spend most of my time in the Bitcoin Technical Support, Development & Technical Discussion, and Bitcoin Discussion sub-forums. I'm much more likely to see your posts in those three sub-forums than any others.
  • Being ACTUALLY helpful in the Bitcoin Technical Support or Development & Technical Discussion sub-forums (without a signature ad) will VERY LIKELY earn you merit from me. HOWEVER, don't try to be helpful if you don't know what you're talking about.  Incorrect information posted in those sub-forums WILL be reported to moderators, will result in me clicking "ignore" on you, and will probably result in your post being deleted by a moderator.
  • Asking well thought out questions in the Bitcoin Technical Support or Development & Technical Discussion sub-forums (without a signature ad) with a sincere interest in learning about something specific that confuses you will VERY LIKELY earn you merit from me.  HOWEVER, nonsense questions, questions that are ridiculously vague, and questions that appear to have no thought or actual interest behind them WILL be reported by me to moderators, will result in me clicking "ignore" on you, and will probably result in your post being deleted by a moderator
  • I ACTIVELY AND INTENTIONALLY AVOID the following sub-forums; Speculation, Off-topic, Politics & Society, and everything in Alternate Cryptocurrencies. Posts in those areas will rarely get noticed by me at all.
  • If you post in a thread that is more than 3 pages long, it's very likely that I'll never see your post. I find that (most of the time) long threads no longer have anything new or interesting in them.  Therefore, unless I've been actively following an interesting conversation in such a thread, I generally won't even bother opening the thread to read anything posted in it.

The Merit system is quite new, and I'm still trying to think through all the pitfalls and benefits.  As such, this post is likely to change over time.  That being said, I've made a few preliminary decisions about how I am going to handle the Merit sending process.  I'm setting my policy here so that it is publicly available:

Policy: The vast majority of Merit that I send will be 1 2 Merit points.

Reason: There are MANY quality posts on this forum, and a limited amount of Merit to award. High quality posts will already earn a significant amount of Merit since they will receive Merit from many users.
EDIT: I am finding it difficult to find enough merit deserving posts to use up my sMerit as fast as I receive it.  As such, I've decided to increase the default Merit that I send from 1 Merit to 2 Merit.  This means that anyone that receives Merit from me will receive AT LEAST 1 sMerit as well.

Policy: As an exception to the previous policy, I will award additional Merit points at my own discretion to posts that teach me something that I didn't already know (and which I wanted to know) about Bitcoin or cryptocurrencies.

Reason: Any post that teaches me something new is highly valued by me, and allows me to better help others.

Policy: If, unsolicited, you send me a PM request ing that I review a post to potentially assign merit, I will NOT review the post and I will add you to a personal DO NOT MERIT list, and I will not send you ANY merit for ANY posts for a period of 3 months.

Reason: I'm concerned about the possibility of my message inbox being flooded by people hoping to get my attention so they can get merit from me.  To discourage this, users that attempt to request merit will be punished with a lack of merit.
EDIT: I have found a need to distinguish between someone that believes a post deserves merit and someone that wants merit without earning it (begging).  Unsolicited request of review of a post will result in NO MERIT.  Begging (See next policy) will result in negative feedback.

EDIT: New policy added
Policy: If you beg for merit (make any request that someone give you merit), you will receive negative feedback from me.

Reason: Merit is intended to be earned.  Begging for it means that you are trying to acquire it without earning it. This is a dishonest way of earning Merit and implies that you are an untrustworthy person.

Policy: I do not sell merit.  Any user that offers to pay me for merit will be PERMANENTLY added to a personal DO NOT MERIT list, and will receive negative feedback.

Reason: If someone is offering to buy merit from me, then it is almost certain that they are offering to buy merit elsewhere. The fact that they may acquire undeserved merit will offset any merit that they would actually have otherwise earned from me.  Furthermore, it is my opinion that purchasing merit (or offering to do so) is an untrustworthy behavior and therefore is deserving of negative feedback.

Policy: If someone identifies a substantive error (not a spelling error, or grammar error) in a post of mine, and posts a reply with a correction to the error, they will earn Merit.

Reason: Most of my posts are an attempt to help others. I can be busy or distracted at times and make mistakes in what I write.  Correcting my mistake helps the person that I was trying to help, and deserves Merit for keeping me from accidentally misinforming the person I was attempting to help.

Policy: Posts in threads that I have already posted in will not earn Merit from me unless I feel they are on-topic for the thread AND I feel they add significant value beyond what has already been said in the thread.

Reason: I'm concerned about the possibility that users will post in threads that I have participated in just to catch my attention to get Merit from me. If your thread is not on topic for the thread, then it should be a new thread.

Policy: Posts in threads that already have more than 60 posts will not earn Merit from me unless I feel they are on-topic for the thread AND I feel they add significant value beyond what has already been said in the thread.

Reason: As threads get excessively long, the likelihood shrinks that a user will read far enough into the thread to benefit from new posts to the thread.  The best, most well thought out, most eloquent post isn't very useful if nobody that cares ever reads it.

Policy: If you have already received 10 merit points from me in a given month, then I will not be sending you additional Merit points in that same month unless I have more send-able Merit points remaining than 10X the number of days left in the month.

Reason: If you have received 10 Merit points from me, then you are very likely receiving Merit from plenty of others as well. As such, I'd like to reserve at least 10 points per day for other users that are deserving of Merit and which have not received as much from me yet.

If you have any suggestions on changes or additions to my policy, feel free to add them to this thread.  Any posts in this thread that are NOT for the purpose of suggesting improvements to my policies will be removed.
14  Other / Meta / Merit test on: January 25, 2018, 02:58:26 PM
This is a test to find out if it is possible for a user to convert their sMerit into Merit by sending merit to themselves...

Edit: Confirmed, users will not be able to send merit to themselves.
15  Bitcoin / Bitcoin Discussion / Mycelium QR Code scam on: January 05, 2018, 09:38:13 PM
I know the forum frowns on duplicate posts, but this is important enough that it seems appropriate for it to be in BOTH the Mycelium subforum AND here.

I encountered malware of some sort on iOS that replaces the QR Code displayed by Mycelium with a scam code.

Details in my post at this link:

Engaged in a transaction with someone today.

- snip -

As far as I can tell, they must have some sort of malware on their phone, or some hacked version of Mycelium that is replacing the QR Code with a scam code.

- snip -

Lesson learned the hard (and VERY expensive) way...

Of course, if someone finds a way to replace BOTH the QR Code AND the displayed address, then there would be no way to know that the address is wrong.  But until then, if the code doesn't match the written address, do not send the bitcoins!
16  Bitcoin / Mycelium / QR Code replacement scam on: January 05, 2018, 09:28:28 PM
Engaged in a transaction with someone today.

They opened up their Mycelium wallet on iOS (looked like an iPhone 6+ or 7+).

I opened up Mycelium on my phone.

They chose "Receive" and I chose "Send".

I scanned the QR Code that was displayed in their Mycelium app.

I added the amount, adjusted the fee to "Priority", and tapped on "Send".

The transaction was sent and quickly gained 3 confirmations according to my wallet.


Their wallet never showed the transaction as arriving.

After about an hour of trying to figure out what was going on, I saw (looking at a block explorer website) that the funds were forwarded on to a new address!

Another 15 minutes of investigation and we discovered that the address displayed by Mycelium did NOT match the QR Code displayed by Mycelium.

As far as I can tell, they must have some sort of malware on their phone, or some hacked version of Mycelium that is replacing the QR Code with a scam code. Unfortunately, they weren't willing to complete their end of our transaction since they felt they hadn't been paid. I wasn't ready to fight them over their own stupidity and lack of sufficient security on their phone. Therefore, I'm out the bitcoins and received nothing in exchange.  Their mistake, and yet I suffer for it.

Lesson learned the hard (and VERY expensive) way...

Of course, if someone finds a way to replace BOTH the QR Code AND the displayed address, then there would be no way to know that the address is wrong.  But until then, if the code doesn't match the written address, do not send the bitcoins!
17  Bitcoin / Development & Technical Discussion / Transaction Quantity Anomaly on: December 30, 2017, 06:04:58 AM
EDIT:  Re-posted because I forgot to mark the previous post as "self-moderated".

Perhaps this has already been discussed, and I've just somehow overlooked the discussion about it in the past?  If so, let me know and I'll lock this thread.

I was looking over the transaction volume at various fee levels at the following site:

I noticed a behavior for which I'm lacking a good explanation.

In the first 4 to 5 minutes after a block is solved, there is a sudden surge of transactions received at the 5 ĶBTC per byte to 7 ĶBTC per byte level (approximately 1200 transactions added during that 4 to 5 minute period). The rate of transactions at that fee level appears to be approximately 240 transactions to 300 transactions per minute.

Then until a block is solved, the number of transactions added at that fee level SUDDENLY drops to less than half that rate, about 100 transactions per minute.  As soon as a block is solved, there is another burst of about 1200 or so transactions at the high 240 transactions to 300 transactions per minute for 4 or 5 minutes again.

I don't see this sudden post block burst at any other fee rate right now.  The transaction count at all the rest of the fee levels seems to grow the same rate consistently.

It is difficult to see any detail on the charts that go back more than a day, so I'm not sure if the same behavior can be seen at different fee levels when the average fee level is higher or lower.

Does anyone have any good explanations of why there would be a temporary 4 to 5 minute burst of so many transactions at such a high fee level immediately after EVERY block, or why the rate of new transactions at that fee level would consistently and suddenly drop after 4 or 5 minutes?

You can see the effect in the chart below where the slope of the blue section suddenly changes:

18  Other / Meta / My ignore list is too long? on: October 23, 2017, 02:03:27 PM
It appears I am no longer able to access my "Ignore user options" page from my profile.

Every time I try, I get:
Busy, try again (504)

Is this a general forum problem that everyone is experiencing, or has my ignore list gotten so large that the forum is no longer able to access it?

Regardless of the cause, is this something that can be repaired in the near future?

If it can't be easily and quickly repaired, then is there some way I can get a copy of my ignore list sent to me occasionally?  Perhaps an API URL I can access, or perhaps I can have a moderator, administrator, etc email the list to me?

Note, I intend to share the list, and will find another way to obtain it if nobody from the forum can help me.  Therefore, if the size is the problem, then other users may begin to have a similar problem soon.
19  Bitcoin / Bitcoin Discussion / MtGox Bitcoin Cash on: August 03, 2017, 02:39:14 PM
Just had a thought...

There are people that are still waiting for the bankruptcy proceedings to complete on MtGox so they can receive their compensation (likely pennies on the dollar). That means that the law firm handling MtGox bankruptcy has access to a bit more than 200,000 BTC.

Since MtGox users had no expectation of a coin split prior to company filing for bankruptcy...

Who owns that Bitcoin Cash?
Can it be sold to aid in the compensation of the MtGox users?
If so, what process should be used for chosing the right time for the law firm to sell it? Immediately? At the time of payout? Some other time?
Is the law firm even aware of their ability to access that added value yet? Have they made any statements about it?
20  Bitcoin / Bitcoin Discussion / 3Blue1Brown YT video explaining Blockchain basics on: July 07, 2017, 07:00:01 PM
Encountered this great video today that explains a lot of the details about how blockchains work.

I felt it was well thought out and well put together.  I'll probably be referring others to it when they have questions in the future.

The creator has BTC, ETH, and LTC addresses listed in the notes below the video, so I went ahead and made a contribution.  Perhaps considering doing that yourself if you find the video helpful.
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