Which algorithm is primarily used for signing and operates similarly to RSA (Rivest, Shamir, and Adleman) but is based on logarithmic and modulus mathematics?

The Digital Signature Algorithm (DSA) is primarily used for signing and operates similarly to RSA in that it utilizes mathematical concepts including logarithmic and modulus operations. DSA is specifically designed for creating digital signatures and relies on the discrete logarithm problem for its security, making it a suitable choice for signing messages. This algorithm provides a method to verify the integrity and authenticity of a message without exposing the private key used to sign it.

DSA performs its signing process by generating a signature from a hash of the message combined with random values and mathematical calculations that involve modular arithmetic. This allows for the secure verification of the identity of the sender through the use of public keys.

In contrast, options like Diffie-Hellman and Elliptic-Curve Diffie-Hellman are primarily used for secure key exchange rather than digital signatures. While RSA is also used for digital signatures, the question specifically asks for an algorithm that operates similarly to RSA but is based on a different mathematical foundation, which is where DSA aligns perfectly with that criterion.