Add the changelog

CHANGELOG.md

@@ -6,16 +6,26 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- `SecretKey` and `SecretKeyFactory` no longer implement `SerializableToArray`, but implement `SerializableToSecretArray` instead. Correspondingly, in the bindings these objects implement `to_secret_bytes()` instead of `__bytes__()` (for Python), and `toSecretBytes()` instead of `toBytes()` (for WASM). ([#53])
+- `SecretKey`, `SecretKeyFactory` and `Signer` do not implement `PartialEq` anymore. Corresponding methods in the bindings were removed as well. ([#53])
+- Bumped `k256` to `0.9` and `ecdsa` to `0.12.2`. ([#53])
+
+
 ### Added
 
 - Added separate entry points for Webpack and Node.JS in the WASM bindings, and added examples for both of these scenarios ([#60])
+- `SecretBox` struct, a wrapper making operations with secret data explicit and ensuring zeroization on drop ([#53])
 
 
 ### Fixed
 
 - Turned off `wasm-bindgen` feature of `getrandom` crate ([#56])
+- Multiple internal changes for safe secret data handling using `SecretBox` ([#53])
 
 
+[#53]: https://github.com/nucypher/rust-umbral/pull/53
 [#56]: https://github.com/nucypher/rust-umbral/pull/56
 [#60]: https://github.com/nucypher/rust-umbral/pull/60