A digital signature in cybersecurity serves as a key mechanism for verifying the authenticity and integrity of digital messages or documents. It employs cryptographic techniques, ensuring that the sender's identity is confirmed and that the message has not been tampered with during transmission. Digital signatures are crucial in facilitating secure transactions and e-commerce, as they prevent fraudulent activities and ensure non-repudiation, meaning the sender cannot deny sending the message. In many cases, digital signatures are legally recognized, making them essential for regulatory compliance in various industries.