How does 'end-to-end encryption' fundamentally protect data transmitted via messaging apps?

'End-to-end encryption' (E2EE) fundamentally protects data transmitted via messaging apps by ensuring that only the sender and recipient can read the messages. The messages are encrypted on the sender's device and can only be decrypted on the recipient's device, using cryptographic keys that are unique to the communication between those two parties. This means that even the messaging app provider, or any third party intercepting the data in transit, cannot decipher the content of the messages. For example, when you send a message using an end-to-end encrypted messaging app, your device encrypts the message using a key that only your recipient's device possesses the corresponding key to decrypt. The encrypted message is then transmitted through the app's servers, but the servers cannot decrypt it. Only the recipient's device, using its private key, can decrypt the message and display it in readable form. This protects the confidentiality of the communication from eavesdropping or unauthorized access.