Digital Signature

November 21, 2023 - Around 2 mins mins to read

Understanding Digital Signatures

A digital signature is a cryptographic technique that is used to verify the authenticity of a digital message or document. By validating a signature, it can be determined that the communication is indeed from the claimed sender (known as authentication), the sender cannot deny their involvement in the communication (non-repudiation), and the communication has not been altered or tampered with (integrity).

Digital signatures rely on public key cryptography, which involves the use of pairs of public and private keys for encryption and decryption. Public keys are made available to the public, while private keys are kept confidential.

When signing a message with a digital signature, the sender uses software to generate a hash of the message. This hash is then encrypted using the sender’s private key. To verify the message, the encrypted hash is decrypted using the sender’s public key. A second hash of the message is created, and if it matches the decrypted hash, the message is considered valid.

It is important to note that digital signatures are different from electronic signatures, although the term “digital signature” is often used to refer to electronic signatures. Electronic signatures encompass any digital mark intended to represent a signature, such as those found in HelloSign and Adobe Sign. However, some electronic signature tools may incorporate digital signature technology, which involves the use of public key cryptography.

Digital signatures are widely used online, especially for authenticating network connections. They are also becoming increasingly common in government operations. For example, the U.S. Government Printing Office now publishes important documents with public signatures to verify their authenticity.