You heard me right, no need to double-check your hearing or sanity levels. In this guide, we’ll explore the concept of creating digital signatures without using any randomness whatsoever (gasp!).

Now, before you start questioning my intelligence and sanity, let me explain how it works. Traditional digital signature algorithms like DSA and ECDSA use a secret key to generate a unique value for each message being signed. This value is then combined with the hash of the message using some mathematical magic to produce a final signature that can be verified by anyone who has access to the public key corresponding to the private key used in generating the signature.

However, this process requires a source of high-quality randomness, which can sometimes be difficult or impossible to obtain in certain environments (e.g., embedded systems with limited resources). This is where deterministic digital signatures come into play they allow us to generate signatures without any need for randomness!

So how do we achieve this? Well, instead of using a secret key to generate a unique value for each message being signed, we use a fixed set of values that are predetermined and known in advance. This means that the same input (i.e., hash of the message) will always result in the same output (i.e., signature), regardless of whether it’s generated by Alice or Bob.

This might sound like a security nightmare, but don’t worry bro!! The beauty of deterministic digital signatures is that they retain all the cryptographic security features associated with traditional DSA and ECDSA signatures. In fact, entities that verify these signatures need not be aware of the process used to generate them they can simply use unmodified verifiers (i.e., software or hardware devices designed for traditional digital signature verification)!

Deterministic DSA and ECDSA do not require any extra storage requirements for secret or public values. This means that you don’t need to worry about storing additional data on your device (which can be a major concern in embedded systems with limited memory).

So how does this work? Well, let me give you an example. Let’s say Alice wants to sign a message using deterministic DSA or ECDSA. Instead of generating a unique value for each message being signed, she uses a fixed set of values that are predetermined and known in advance (i.e., the same input will always result in the same output).

Here’s how it works:

1. Alice computes the hash of the message using a cryptographically secure hash function (e.g., SHA-256 or SHA-512) and stores this value as H(m).

2. She then applies some mathematical magic to generate a deterministic signature, which can be verified by anyone who has access to her public key. This involves using the same set of values for each message being signed (i.e., no randomness is used).

3. The resulting signature is sent along with the original message and H(m) to Bob or any other entity that needs to verify it.

4. When verifying the signature, Bob uses Alice’s public key to compute a value called v’. This involves applying some mathematical magic using the same set of values used by Alice (i.e., no randomness is needed).

5. If v’ matches the value sent along with the original message and H(m), then the signature is considered valid!

No need for any fancy math or complex algorithms, just a simple and straightforward approach to generating signatures without using randomness. And best of all, they retain all the cryptographic security features associated with traditional DSA and ECDSA signatures!