Signing and verifying any data with ECDSA

[mamuu]

Hello, I have been developing mathematics with information from here for a long time. Thank you.

I'm producing a software now.

I have program "A"
There is a program "B" written by someone else elsewhere.
These softwares work over the web.

A function inside the "B" program runs when data comes from "A".


Let "A" have data ("11") and send it to "B"

Program "B" will trigger the "start()" function if the data "11" belongs to "A", but the "exit()" function will work if it does not belong to "A"?

It doesn't matter what language I use, I want to verify data on any webserver.
I've tried a few solutions but I've had a little bit of difficulty. How can this be confirmed with ECDSA? It's like processing a crypto wallet

[1714561120]

1714561120

[pooya87]

First B has to know A's public key. Each time that A sends any data to B it also signs that data with its key and sends both the data and the signature so that B can first verify the signature to make sure it is from A.

Without knowing what A and B are and what they are supposed to do and whether they communicate with each other only or also with others (C, D, ...), etc. it is not possible to give the best solution which may be using something like SSL where A encrypts the data before sending it instead of signing it.