What the HTTPS padlock means: how your browser talks in secret on a Wi-Fi anyone can read
Encryption: how HTTPS turns every message into nonsense for everyone but the website
The padlock shows in your browser. A stranger on the same Wi-Fi still catches every message your phone sends. But now each message looks like random letters. Only the website can read it.
-
1
The change happens inside Miva's phone, before a packet leaves. The phone scrambles its words with a key, a long secret number. Scrambling a message so that only holders of the key can read it is called encryption.
-
2
Rono's copy is a jumble of signs. To read it, he would have to guess the key, and there are far too many possible keys for any computer to try them all.
-
3
At the other end, the shop's server holds the very same key. It runs the scrambling backwards, and the card number comes out as Miva typed it. One key locks, and the same key unlocks.
-
4
There is a catch. Miva's phone and the shop had never talked before tonight, so neither one had the key. And if one of them sent it over the Wi-Fi, Rono would catch it like every other packet.
-
Quick check
Rono catches the shop's answer on its way back to Miva. Can he read it?
Show the answer
No. The shop scrambles its answer with the same key, and Rono does not have it.
-
Go further
Two names for what you just saw.