I know, I know, "why?" is the right response, but building a bitcoin ECDSA calculator in excel without using macros or array formulas was something I wanted to do

I made a spreadsheet that performs bitcoin's ECDSA calculation and now share with the community as a tool for learning more and diving into how the secp256k1 curve works

Is this the first time its been done?  I haven't seen anything like it anywhere so I think this is the first.  Happy to talk about the long process it took to get to this point

It is a pretty big spreadsheet (over 120MB), but it works from what I can tell.  it takes that many MB just to make one point addition, so one has to copy/paste points to move around the curve (up to 255 times lol)

Fair warning--don't use it for holding bitcoin--this is why I didn't create the public key part (yet)

You can find it on my website:  https://modulo.network

I was looking through ECDSA math and feel like I am missing something related to the x,y coordinates of a public key, searched around but did not find answers so coming here hoping for some help / guidance.

My question is:  Is there a private key where the y coordinate of the public key created through the ECDSA secp256k1 curve ever a negative y?  From what I can tell is 'no', but then I wonder why even bring the sign into the bitcoin code as a prefix?  I must be missing or misunderstanding something.

What leads me to think this way is how mod function attached to determination of a y coordinate as well as numerous examples and attempts.

Thanks

Hi, first post here, so hopefully it doesn't get run over too badly.  Let me precede the question with an explanation that although the question has a mining-related driver, this is not a mining question but a request for help on how to Post a submitblock RPC(?) to the bitcoin network.

Background is, I recently created an excel spreadsheet for a fun, interactive way to run the bitcoin mining process (https://modulo.network); I believe this is the first time someone has done this.  I did it not just to learn myself, but to attract others to bitcoin by demystifying how the mining process works and encourage people to run their own nodes for posting successful submitblock results, and earn a little bitcoin at the same time.  If some users of the spreadsheet do not want to run a node, I thought it would be useful to offer a window on the aforementioned web page where they could post a successful block to the bitcoin network.

I went through this thread and searched within the bitcointalk forum and found this thread, (https://bitcointalk.org/index.php?topic=5235026.0), but it doesn't look like the tool exists.  I don't want to repeat the work if it already exists and would like to leverage what is out there, and if it doesn't exist, would anyone be able to help me set this up?  My web page instance is on WIX, and any development like this needs a real computer engineer, not a novice like myself