Digital Signature

A Digital Signature is the electronic equivalent of a traditional handwritten signature, and its function is to certify the validity, truthfulness and authorship of a document. From a more technical standpoint, a digital signature is a type of electronic signature, which is based on a cryptographic key mechanism. As a specific type of electronic signature, it’s able to offer a very high level of security.

This system allows us to no longer have to manage documents in paper form, thus streamlining communications between public authorities, individuals and companies.

Thanks to the digital signature, it is possible to confer legal validity to the most diverse digital documents: contracts, declarations, public and private administrative documents. The digital signature guarantees the authentication of the sender, the non-repudiation of the message and its integrity.

The most basic scheme of an electronic signature is generally made of three algorithms.

1. The first one involves the generation of public and private cryptographic keys. The private key is the one with which the document is signed, while the public key is used for digital signature verification.
2. The second signature algorithm involves calculating the hash code of a message and encrypting it with the private key, in order to produce a signature.
3. The third algorithm plays the role of a “digital signature verifier” since it takes the message input, the public key, and the signature to determine whether it will accept it or not.