A digital signature is often used to authenticate the identity of a person who signs an electronic document or sends an electronic message. A digital signature also ensures that the contents of the electronic document remain unchanged. Digital signatures are made secure using encryption technology which can not be faked or easily compromised. Digital encryption keys are used to encrypt and decrypt data, ensuring that sensitive information is not tampered with or altered. Digital signatures are routinely used for electronic contracts and when transmitting sensitive information online. They are more secure than standard electronic signatures, which can refer to any mark or process that signifies agreement. The rise of e-commerce online has led to a decrease in the use of paper forms and contracts, and digital signatures have begun to take the place of handwritten signatures. Using digital technology saves precious natural resources and can speed up the time it takes to process contracts. Federal laws such as the E-Sign Act give legal validity to electronic and digital signatures, assuring that they are held to the same legal standards as handwritten signatures.