ML-DSA vs SLH-DSA: Which to Choose Cryptography ML-DSA vs SLH-DSA: Choosing Your Signature Algorithm 14 min read What Are Digital Signatures, and Why Should You Care? Imagine you receive a letter in the mail. How do you know who actually sent it? Someone could have forged the return address. How do you know nobody opened the envelope, changed a few words, and resealed it? In the physical world, we have notaries, wax seals, and registered mail. In the digital world, we have digital signatures. A digital signature is a piece of math attached to a file or message that proves two things. First, authenticity : the file genuinely came from the person or organization claiming to have sent it. Second, integrity : the file has not been changed, even by a single bit, since it was signed. If someone modifies the file after signing, the signature check fails. You rely on digital signatures constantly, even if you never think about them.…