I think from what I studied that I had the correct reasoning, but I would like a double check. Here is the thing:

Given two matrix: A and B

I calculate the hashFunction(A, B) = C

Now I calcultate the eigenvalues of B: µ and the associate vector x

Now is the following equation correct:

C * x = hashFunction(A, µ) * x = hashFunction(A, µ*x)

Is it true given any hashfunction? Specifically given sha256, or Elliptic Curve Function, or any other?


My aim is, given a public information, to show that I am the owner of the information and gives other information, and avoids that if someone intercepts the password I give before it comes to the audience, he cannot uses it to gives different information.

So for the problem I gave, data are:

B is public

TO authentify me, I give hash(A, µ) and x

2nd EDIT

The answer to my question seems to rely in Signature as described in this paper. Has anyone an example of signature and verification algorithms ?

3rd EDIT:

So I implemented something, could it be use

PRIVATE_KEY = base64.urlsafe_b64encode(key.encode("utf-8"))


  • $\begingroup$ It is $$\text{By no means}$$ What is your aim? $\endgroup$
    – kelalaka
    Dec 30, 2021 at 23:03
  • $\begingroup$ @kelalaka do you mean the equation is false? even two first members? $\endgroup$ Dec 30, 2021 at 23:04
  • $\begingroup$ sha256 is nonlinear - so, what do you mean by an 'eigenvector'? And, why do you expect sha256 to exhibit them? $\endgroup$
    – poncho
    Dec 30, 2021 at 23:10
  • $\begingroup$ the eigenvector is associated with the eigenvalue µ that is in fact my question: would it be possible with another crypto algorithm that still avoids to find back A and B given C ? $\endgroup$ Dec 30, 2021 at 23:16
  • 1
    $\begingroup$ What is your aim, this is more important. In multi-party computations, there are tons of protocols to achieve various aims... $\endgroup$
    – kelalaka
    Dec 31, 2021 at 13:34

1 Answer 1


I'm not quite sure if I understand your question correctly, but all you need is to generate a Public and Private Keys, then share Public key and Sign your document with your Private key. This way, everybody knowing your Public key will be able to verify, that document is signed by you (i.e. the one who knows Private Key).

  • $\begingroup$ Thank you this is what I searched for but would you have practical examples of that? Like algotrithm or code to sign the document? to verify the signature? $\endgroup$ Jan 2 at 20:04
  • $\begingroup$ Hi I edited the question with a little code, could you please tell me if it is in accordance with the SIgnature thing? $\endgroup$ Jan 16 at 10:25
  • 1
    $\begingroup$ @totalMongot See en.wikipedia.org/wiki/Digital_signature. For an example of software that implements digital signatures, check out GnuPG. $\endgroup$
    – eesiraed
    Feb 16 at 3:23

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