Definition
A method of securing digital information by using a matched pair of cryptographic keys: a public key that can be shared openly and a private key that is kept secret. Information encrypted with one key in the pair can only be decrypted with the other. In aviation, PKI is used to verify the authenticity and integrity of electronic data such as signed flight procedures, electronic flight bag content, and secure communications between aircraft and ground systems.
Plain English
A way of locking and unlocking digital information using two matched keys. One key is shared with everyone; the other is kept private. This proves the data is genuine and has not been tampered with.
Context Anchor
Seen in aviation documentation involving secure electronic data, digital approvals, protected communications, or trusted information systems.
Derivation
From cryptography: 'public key' and 'private key' refer to the two halves of a mathematical pair. 'Public' because it is meant to be shared; 'private' because it must be kept secret. Knowing this distinction helps the term make sense at a glance.
Why Pilots Care
It protects against spoofed or altered electronic flight data, ensuring pilots can trust the information they receive.
Analogy
Think of it as a mailbox with a slot anyone can drop mail into, but only the owner has the key to open it.
Intuition Check
Public and private do not mean two separate messages. They mean two linked electronic keys: one can be shared, and the matching one must be kept secret.
Example Sentence 1
The avionics manufacturer uses PKI to digitally sign chart updates so the flight management system can confirm they are genuine before loading.
Example Sentence 2
Ground stations rely on PKI certificates to confirm the identity of aircraft transmitting position reports.