TinkerFull handshake. Page in 176 ms.1,200 km · 8 trips to the shop · 176 ms
Chapter 5 of 7
The sealed envelope
The line is open, but anyone along the way could read it. Larkspur’s page carries prices and orders.
This chapter: What does HTTPS add, what does it cost, and what does the padlock prove?
About this chapter
You will learn
- TLS seals the line and checks the shop’s certificate
- Resuming a session saves a round trip, for safe requests only
- What the padlock proves, and what it doesn’t
Words you’ll meet
- TLS
- Transport Layer Security: it encrypts the line and proves the server’s name.
- Certificate
- A signed card that ties the shop’s name to its key.
- Certificate authority
- The seal office: a body browsers trust to sign certificates.
- Session resumption
- Reusing keys from an earlier visit, so a returning browser can start sooner.
- 0-RTT
- Zero round trips: a resumed browser sends its request with its very first message.
Step 1 of 5
seals the line: one more round trip agrees keys and shows a , signed by a .
Check the certificate.