Act of attaching a signature by electronic means. The e-signature process involves authentication of the signer’s identity, a signature process according to system design and software instructions, binding of the signature to the document, and nonalterability after the signature has been affixed to the document. Types of e-signatures are (1) simple, electronic image of a person’s signature; (2) digital signature—a more complex, technology-specific electronic signature that uses a level of authentication to verify that the person sending the information actually owns the signature; this type of signature is similar to a public key infrastructure and uses the exchange of keys (i.e., digital certificates and encryption algorithms) for authentication; and (3) the “click here if you agree” section of online click-through forms.