1. The document discusses the history and development of electronic signatures, from encoding messages to modern cryptography. It describes how asymmetric cryptography and public/private key pairs enabled electronic signatures by verifying the identity of the sender. 2. An example is given of obtaining a cryptographic USB key from a Trusted Third Party to digitally sign documents and emails. Integrity is ensured as signatures cannot be altered without invalidating the signature. 3. Examples of using electronic signatures include signing contracts between call centers and offshore companies, signing sales proposals from banks to customers, and signing insurance contracts online with time stamping and IP address verification. Electronic signatures provide security, proof of origin, and increase conversion rates.