0 views collected around this technical thread.
The article uses a classroom love‑note scenario to illustrate how single‑key (symmetric) and double‑key (asymmetric) locks model modern cryptographic techniques, explaining key exchange, signatures, man‑in‑the‑middle attacks, and how HTTPS secures communication.
The article explains Diffie‑Hellman key agreement, detailing its 1976 origin, mathematical derivation, example walkthrough, and provides complete Java server and Android client code illustrating how two parties securely generate a shared secret over an insecure channel without transmitting the key.
Baidu’s bdtls protocol adapts TLS 1.3 for mini‑programs, delivering mutual authentication, AES‑128‑GCM encryption, RSA‑signed Diffie‑Hellman key exchange, sub‑10 % handshake latency, and extensible multi‑business support to defend against static, dynamic and cheating attacks while ensuring high availability.
This article provides a comprehensive introduction to cryptographic techniques, covering the goals of confidentiality, integrity and authentication, and detailing symmetric, asymmetric and hash algorithms, common implementations, their advantages and drawbacks, as well as key exchange methods and public key infrastructure.