Added Security

Author: jamesgober

CHANGELOG.md

@@ -11,13 +11,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Cross-platform support for local transport (Windows compatibility)
 - Windows-compatible alternative for Unix Domain Sockets using TCP
 - Updated client and server binaries to work across platforms
+- Secure handshake protocol using ECDH key exchange
+- Protection against replay attacks using timestamps and nonce verification
 
 ### Changed
 - Improved error handling in client/server binaries
 - Updated format strings to use modern Rust syntax
 - Fixed Clippy warnings throughout the codebase
 - Added Default implementation for Dispatcher
 
+### Security
+- Implemented Elliptic Curve Diffie-Hellman (ECDH) key exchange using x25519-dalek
+- Added timestamp verification to prevent replay attacks
+- Enhanced key derivation using SHA-256 and multiple entropy sources
+- Ensured forward secrecy with ephemeral key pairs
+- Deprecated the previous insecure handshake implementation
+
 ## [0.9.0] - 2025-08-17
 
 ### Added
@@ -34,5 +43,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added encryption for protocol messages
 
 [Unreleased]: https://github.com/jamesgober/network-protocol/compare/0.9.0...HEAD
-[0.9.1]: https://github.com/jamesgober/network-protocol/compare/0.9.0...v0.9.1
+[1.0.0]: https://github.com/jamesgober/network-protocol/compare/v0.9.9...v1.0.0
+[0.9.9]: https://github.com/jamesgober/network-protocol/compare/v0.9.6...v0.9.9
+[0.9.6]: https://github.com/jamesgober/network-protocol/compare/v0.9.3...v0.9.6
+[0.9.3]: https://github.com/jamesgober/network-protocol/compare/0.9.0...v0.9.3
 [0.9.0]: https://github.com/jamesgober/network-protocol/releases/tag/0.9.0

Cargo.lock

@@ -45,6 +45,13 @@ tracing = "0.1"
 getrandom = "0.3.3"
 rand = "0.9"
 
+# Cryptographic dependencies
+x25519-dalek = { version = "2.0", features = ["serde"] }
+sha2 = "0.10"
+once_cell = "1.8"
+rand_core = "0.6"
+rand_chacha = "0.3"
+
 bincode = "1.3"
 bytes = "1.5"