GETTING EDGY VIDEO SERIES

Getting Edgy: Understanding Transport Layer Security (TLS) Encryption

Learn about how to keep your users’ information safe on the web.

In today’s episode, we discuss how TLS encryption works between a client and a server.

Encrypted Activity

Websites with Transport Layer Security (TLS) encryption ensure you, as a user, can visit a website without having your personal information stolen. If you’re on a mobile phone or a browser on your desktop and you see a green padlock in the URL bar, this means that your activity is encrypted and your personal information is safe.

But how exactly does that happen?

The Process

The way in which you are accessing the internet is called the “client.” The client contains security details, such as a cipher, and sends a hello message to connect with the server, or the web destination you are trying to reach.

The server responds with its own hello message, and picks a piece of information from the client-side, such as the cipher, to authenticate with. It also sends a digital certificate from a legal and trusted Certificate Authority.

This certificate has a public key, which is sent to the client, and a private key, which the server keeps. Public and private keys work together in pairs, in that the public key always encrypts something, and the private key can always decrypt it.

The client validates that the certificate is trusted and then generates something called an encrypted premaster secret, using a public key from the certificate.

The server uses private key to decrypt the premaster secret and generates a session key, indicating that it is ready for communication. The client generates its own session key, which should be identical to the server session key, to also indicate that it is ready for communication.

At this point, all communication between the server and the client is secure thanks to TLS encryption.

Learn more

• Ambassador Doc: TLS
• Ambassador Doc: TLS Origination
• Ambassador Doc: Mutual TLS
• Using Ambassador and Linkerd2 for Service Discovery and end-to-end TLS
• Using TLS and SSL Termination in Kubernetes with Ambassador
• What is TLS?

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