https://bitcointalk.org/index.php?topic=5213659.0
Happy 2020

Edit: This puzzle is solved and the reward was claimed by hatshepsut93, congratulations. You can read the technical details in this post. Hope everyone enjoyed this and maybe learned a thing or two.

A couple of days ago I found myself among kindred souls in a topic in meta board talking about signing messages and whatnot. Kudos to DdmrDdmr that gave an idea for a fun little brain teaser for those who have a keen sense of adventure, a knack for solving puzzles and are not afraid to peep through the keyhole to kick start the year with their knowledge increased or boost your karma.
In order not to kidnap that thread anymore, I’ve started a new topic here.
As we approach 2020, whether you are celebrating Christmas with pine kones or Kwanzaa with a kerosene candle you can still kneel beside the fire with a keg of eggnog while warming your knuckles with kindling to solve a puzzle.


As the year us 2020, 20 merit reward shall be waiting for he who can figure out what two mysteries are hidden in this. 10 per mystery
Happy 2020 everyone...

Here is a small puzzle to solve in the holiday. Try to figure out what is interesting about this message and receive up to 20 merits from me. There is 2 interesting parts, 10 merit per part
Happy 2020 everyone.

This shall have its own topic https://bitcointalk.org/index.php?topic=5213659.0

My new year's resolution is to limit the number of projects I have to a manageable number and do more releases.
I will release 2 new projects in 2020 that are mostly an aggregation of nearly all of the projects both released and unreleased that I have made in that past 3-4 years.
Since both of these projects are written from scratch the development is going to be slow although I have written most the code already it still requires lots of testing, optimization and some other considerations. Because of that I will try a new approach of releasing the code first and then adding/changing it as I go. I'll also introduce a new versioning convention to keep things clear.

The 2 new projects are:
1. The FinderOuter:
it is referred to as "SharpCracker" here, and it starts by focusing on bitcoin first and will have limited options but eventually I plan on adding more flexibility to it so it could be used for altcoins too.
The project covers StellarCracker and AddrConverter and Sharp Crypto projects.
Project link: https://github.com/Coding-Enthusiast/FinderOuter
Release date: 2020-01-01

2. Denovo:
This will be a full client that would include features of "Watch Only Bitcoin Wallet", "Bitcoin Transaction Tool", "Sharp Pusher", "Cryptocurrency.Net" and a lot more.
I have not yet decided whether to make it a multi-cryptocurrency project or only bitcoin. It will start with bitcoin though with flexibility to be changed in the future.
Release date: if things go well I'll release it in first couple of months of 2020.

Not as new as you might think. We are using TestNet "3" for that reason. It has happened before on a larger scale and nowadays I am seeing an increase in some suspicious activities involving TestNet coins which is why I decided to start this topic.

TestNet is an alternate network with the same consensus rules as MainNet and some differences such as being easier to mine, allowing non-standard transactions,... as the name suggests, it exists to help developers test their code without worrying about the costs.

Because of that, the TestNet coins have no value. Be careful not to get scammed like this.

TestNet coins are also easily distinguished since the wallets are different (need to create a new special TestNet wallet) and the addresses use different format (start with: m or n instead of 1 for P2PKH, 2 instead of 3 for P2SH, and tb1 instead of bc1 for Bech32).

https://en.bitcoin.it/wiki/Testnet

You'll have to go through the code and see how ECDSA is implemented in the software you are using. A good way to avoid this bug and a bunch of similar ones is generating k deterministically instead of randomly. One way that is used in most Bitcoin implementations is RFC-6979.

Not true. If f(x)=a+b=12 then (a,b) can be (0,12), (1,11), (2,10),...
Things aren't different for modular arithmetic. Here is an example:

s = k^-1 * (e + r*key) % N
N=17

e=4; key=7; k=1; r=7 => s=2
e=4; key=7; k=2; r=0 => s=2
e=4; key=7; k=3; r=10 => s=2

e=12; key=3; k=1; r=8 => s=2
e=12; key=3; k=2; r=3 => s=2
e=12; key=3; k=3; r=15=> s=2

e=12; key=10; k=1; r=16=> s=2

Version 0.11.0 released
- Small bug fixes
- Code improvements and changing the looks of script window, rearranging buttons,... and changed the code to make running scripts separate from writing them.
- Added script templates (4 for now: pubkey scripts based on addresses, OP_RETURN scripts, multi-sig redeem scripts, and the hash collision incentives)

It is because I am not sure how to implement these two as an IOperation. In the near future I will add these OPs and also eventually will release my Cryptocurrency.Net library which would also mean additional features including signing, verification and communication with nodes.

In this topic I was hoping for some ideas on how to improve the user interface. For instance how would you like to create such smart contracts?

I did some search and it seems like Wine has some known bugs related to WPF (GUI that is used in this project). I won't spend any time on fixing this because there is a much better way of solving the issue and that would be using a cross-platform GUI so that you don't need Wine, you simply run it as you run any other application in another OS (Windows, Linux, Mac,...).
Currently there are a couple of them that I'm aware of. The one that I feel comfortable with (also used by Wsabi wallet) is called Avalonia, but since it is in beta, it lacks a lot of functionality or to do certain things you have to bend over backwards (like the grid-like lists where you enter addresses and the list containing UTXOs with categorization and headers).
The migration is in my "roadmap" which would make it easy to run it under any other OS without needing anything else. Meanwhile if someone is familiar with Xaml and Avalonia feel free to contribute...

That is an IDE (development environment, ie. where you write code and compile), what is needed here is a GUI that is a graphical user interface that doesn't require windows APIs (like WPF does) to run.

---

I've released a new version and added description to each button in script writer window explaining what they do. Also the QR window now lets you choose the encoding you want to use (eg. Electrum uses Base43 to encode raw unsigned transactions).
https://github.com/Coding-Enthusiast/BitcoinTransactionTool/releases/tag/0.10.1.0

Of course I recognize my own UTXO anywhere!
Try checking the script window and play around with that too and let me know what you think. I'll try to add more to it this week.

One should not really download and run .exe and since until now nobody had requested compiled version I've never thought about it. In any case I published it using ClickOnce, more info can be found here: https://github.com/Coding-Enthusiast/BitcoinTransactionTool/releases/tag/0.10.0.0

I've tried migrating to Avalonia (a multi platform GUI) but it lacks a lot of functionality specially when it comes to lists, so for the time being this project will remain only for windows. I'll try looking into other alternatives to migrate to .net core entirely which would make publishing and compiling easier too.

It seems like a JSON parsing problem to me. You are giving the interpreter a JSON array (an array of outputs) so it should look like:
where keys are addresses and values are decimal amounts.

It is already on GitHub https://github.com/Coding-Enthusiast/BitcoinTransactionTool
Do you mean publishing the compiled binaries?

You have to look at the buttons that are disabled for it to become obvious. These are a bunch of OP codes (such as OP_CAT, OP_Multiply,...) that were removed/disabled a long time ago. Since their names still exist in the source code and documentation, I also have them here as disabled buttons.

I'm always a fan of simplifying things and building GUIs and ever since I saw the Miniscript project I wanted to make that happen. Since I recently resumed working on one of my oldest projects (Bitcoin Transaction Tool) I decided to add it as a new feature to that project, for writing and running scripts at the same time.

It can be found under Tools > Script builder (or press F3). It currently supports all OP codes except the disabled ones (for obvious reasons) and *checksig OPs (since to support them I had to copy about 6000 lines of code into this project) and 2 locktime related OPs and CodeSeparator (because I haven't had time to understand how they work!). OPs are also categorized and can be filtered by using the ComboBox on top for ease of finding them.
Writing the script will also run it, the result of it is shown in a text box and the "box" at the bottom right is a list representing the "stack".

I plan on working on it and add more more features such as adding pre-defined script that only need filling up the data part. But before that I wanted to get some feedback about what you think about something like this, how can I improve it,...

Here is a preview:

Yes, they are different (in case it wasn't clear, AES is Advanced Encryption Standard). There are hundreds of CPU intrinsics available. You can see Intel's intrinsics here: https://software.intel.com/sites/landingpage/IntrinsicsGuide/
AES is a group of them that they added in a lot more CPUs compared to SHA so it is normal to see old/cheap CPUs support it.

Damn, I was afraid of this. It looks like assembly code and I can't read it. Gotta put it in the to-do list now.

Yeah, I've been reading some benchmarks on this. It's fantastic. It is surprising that only a handful of CPUs have SHA Extensions although Intel introduced it in 2013!

I am currently exploring parallelization of SHA256 algorithm using SIMD based on a paper I've found which is basically parallelization of the "message scheduling" step that according to the authors takes up 26% of the computation time.

If I understand bitcoin core's code (eg. AVX2), it seems like it doesn't support computing SHA256 of a large data using SIMD (eg. SHA256 of a single 512+ byte long data), but only has the code for computing SHA256 of multiple messages in parallel (ie. SHA256 of m1, m2, ..., m8) and return multiple hashes (ie. h1, h2, ... h8).

If I am reading the code wrong, please explain how it does that.
And if I am right then is there any reason why they didn't add this feature? It seems to be useful for computing the message digest of a big transaction specially the legacy ones which could easily be bigger than 512 bytes.

P.S. If you have any scientific paper about this topic that is newer than 2012 please let me know.