To improve end user experience and reduce core network overhead, the concept of Content Distribution Network (CDN) was proposed. The basic idea is to set up many content buffers that are close to end users. Akamai is one of the major players in the CDN market.

To prevent network eavesdroppers from getting access to data during transmission, data encryption is often used in CDN. Please describe how Akamai handles delivery of encrypted contents from the following aspects:

(1) How are the two segments of data encryption, from content source to Akamai and from Akamai to end user, achieved?

(2) How can an end user verify that the contents are delivered by the original source?

(3) Does each end user have their own data encryption key with Akamai or is it a common key shared by all users?