What is e-TS?

Why do we need e-TS?

How does e-TS work?

What is the technology behind?

	Cryptography
	Hashing
	Public Key Infrastructure (PKI)
	Digital certificate
	Digital signature
	Time source

A public key infrastructure (PKI) provides the framework that enables users to exchange information securely and confidentially on the Internet based on asymmetric cryptography.

With asymmetric cryptography, a private/public key pair is created. The private key is given to the requesting party and the public key is made publicly available in a directory that all parties can access.

When someone wants to send you a confidential message, he/she can find out your public key in the directory and encrypt the message with your public key. When you receive the message, you decrypt it with your private key. The use of cryptography ensures the confidentiality of the message. Apart from encrypting messages, you can also authenticate yourself by using your private key to make a digital signature. When the recipient get the signature, he/she can use your public key to decrypt it.

Main components of a PKI:

	Certification Authority (CA): responsible for issuing digital certificates, which is for creating or certifying identities
	Registration Authority: responsible for handling exchanges between the users and the PKI for initial authentication, registration, certificate delivery and other key and certificate management
	Certificate Repository: responsible for storing certificates and certificate revocation lists; used as a directory