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But, What Does A Digital Signature Actually Look Like?

I created the asecuritysite.com website as I found there were very few sites that have practical implementations of the core methods. As a teacher, too, I believe that I should not give students something that I don’t know how to implement myself. And so the Web site has grown, as my knowledge of the field has grown. For me, it is a scratchpad for ideas, and where I want to show that the implementation of fairly complex cryptography methods is actually quite easy to understand. Along with this, things become real when they are made practical.

And so I get a good deal of questions, and one just said, “What does a digital signature actually look like?”.

Well, without going into detail, the most common digital signature is ECDSA (Elliptic Curve Digital Signature Algorithm). Basically, it takes a message (M), a private key (sk), and a random value (k), and produces a digital signature of r and s. These are just two integer values. To check the signature, we take the message (M), the associated public key (pk), r and s, and perform a validation test, and, if it passes, the message has a correct signature.

But what does the signature actually look like?

So what does the signature actually look like? Is it just two numbers r and s that we add to the…