Technical term in computing and telecommunications; refers to encryption where only the communicating users can read the messages.
This messaging app uses end-to-end encryption.
端末間暗号化によって、第三者が通信内容を傍受することはできない。
With end-to-end encryption, third parties cannot intercept the communication content.
Encryption in general; 端末間暗号化 specifically refers to encryption that protects data between endpoints.
Compound of 端末 (terminal, device), 間 (between), and 暗号化 (encryption). A calque of English 'end-to-end encryption'.