libes
library of encryption scheme(s) is a collection of ECIES variants.
The goal of this is library is to become a one-stop shop for everything ECIES.
For code documentation, usage explanations, and examples please see Docs.rs.
⚠️ Alpha Release Track - Not Production Ready ⚠️
During alpha development, versions 0.1.Z, there is no guarantee of backwards compatibility and the API can change at any time. If you decide to use this library at this time, make sure that you always use the latest version, and be prepared to update your usage of the library often.
Why use libes?
The rust cryptography ecosystem is swarming with crates, with varying degrees of quality and documentation. I have taken it onto myself to navigate this, and I want to share my findings with those who are trying to make sense of it like me.
In doing this I commit myself to:
- Maintaining a curated selection of relevant crates
- Verifying that dependencies have not made mistakes in their implementations
- Using dependencies with good performance and a high quality of code and documentation
- Providing a uniform and predictable API
- Using shared constructors in the API to guarantee uniformity
- Guaranteeing long-term support for all major releases
- Striving for a high degree of clarity and detail in the documentation
- Keeping the library up to date & vulnerability-free
- Automatically updating dependencies and testing code
- Prioritizing issues & feedback on implementations
Table of Contents
FAQ
TBD
About
What is ECIES?
ECIES stands for Elliptic Curve Integrated Encryption Scheme. It is a type of cryptographic procedure which allows encrypting data for a specific recipient given only the data to be encrypted and the recipients public key, everything else is derived from the input or generated with a CSPRNG (Cryptographically Secure Pseudo-Random Number Generator).
Wikipedia
Crypto++
Practical Cryptography for Developers
ECIES Variants
Cryptographic algorithms have evolved over time, and thus have grown into two distinct ECIES variants as of writing.
Originally, ECIES relied on a key exchange operation, an encryption operation, and a separate MAC operation.
A MAC (Message Authentication Code) is necessary to provide Authenticity on top of Confidentiality. By exploiting vulnerabilities and/or compromised parameters, encrypted data could potentially be manipulated to produce a desired output, other than what the sender intended. A MAC can be used separately from the encrypted data to verify that such manipulation did not take place.
More recently adopted encryption algorithms like AES-GCM and ChaCha20-Poly1305 are AEAD (Authenticated Encryption with Additional Data) algorithms which in addition to a ciphertext, also produce an Authentication Tag which serves the same purpose that a MAC does in this case, but is integrated in the encryption algorithm itself.
The library and documentation will refer to these two variants as:
- ECIES-MAC (Encryption with MAC)
- ECIES-AEAD (AEAD Encryption instead of MAC)
Iterating further on ECIES-AEAD, it could be further integrated by synthesizing the IV/Nonce rather than generating it randomly. This would eliminate the need to store & transmit the Nonce, as well as reduce the overhead by one or two dozen bytes. Because there is already random data in the ephemeral key, the risk of deriving the same encryption key twice is minimal, and thus it should be safe to do so. This third variant will be referred to as ECIES-SYN.
DISCLAIMER: ECIES-SYN is my own idea, which I will only implement for algorithms that I have done extensive research on to ensure that it is cryptographically secure to do so. Regardless, I am not a cryptography researcher and I can not give a guarantee that issues will not arise in the future. If ECIES-SYN turns out to be useful/popular and resources allow, I will make sure that it receives a security audit.
ECIES-MAC Flowchart
See the README.md on GitHub.
ECIES-AEAD Flowchart
See the README.md on GitHub.
ECIES-SYN Flowchart
See the README.md on GitHub.
SemVer
This library respects SemVer, and guarantees decryption backwards compatibility.
This means that data encrypted using library version X.Y.Z can be decrypted using any superseding library version as long as X is the same.
For example, data encrypted using version 0.5.7 can be decrypted using version 0.5.7 or 0.11.1, but not using versions 1.2.3, 0.5.6, or 0.4.10.
Effort will be made to keep X, the major version, decryption backwards compatible as well, but no guarantee is given.
Release Tracks
- v0.1.Z: alpha - initial strcuture
- v0.(2+).Z: beta - adding algorithms
- v1.0.0-pre.W: pre-production - refactoring & memory zeroing implementation
- v1.0.0: initial production - potentially backwards-incompatible refactoring
- V1.(1+).Z: production - wasm support & more
Conditional Compilation
All algorithm combinations are gated behind features, to reduce how much is being compiled. Features are named exactly like the algorithm names in the support matrices (if there are alternative names like P-521 and secp521r1 then they are aliases, so you can enable either). This library uses traits to implement appropriate functionality on valid user-defined variants.
NOTE: No ECIES variants are available without activating any features, at minimum one of each feature categories must be activated:
- Elliptic Curve (e.g. x25519)
- Encryption (e.g. AES-GCM)
- Authentication (e.g. ECIES-AEAD or HMAC-SHA256)
NOTE: For a ECIES combination to be valid the Elliptic Curve, Encryption, and Authentication algorithms must all support the same ECIES variant.
- To use ECIES-MAC, all three chosen algorithms need a "🚀" in their respective ECIES-MAC columns
- To use ECIES-AEAD or ECIES-SYN both first two algorithms need a "🚀" in the variant column
Algorithm support
Matrix entries are of form Encryption & Decryption or Encryption/Decryption
Support icon legend
- 🚀 Completed
- 🏗️ Development
- 📅 Planned
- 🤔 Planning
- 🚫 Can/Will not implement
Elliptic Curve Support Matrix
| Algorithm/ECIES Variant | ECIES-MAC | ECIES-AEAD | ECIES-SYN |
|---|---|---|---|
| x25519 | 🚀 | 🚀 | 🚀 |
| ed25519 | 🏗️️ | 🏗️ | 🏗️ |
| K-256 / secp256k1 | 📅 | 📅 | 📅 |
| P-256 / secp256r1 | 📅 | 📅 | 📅 |
| P-384 / secp384r1 | 🤔 | 🤔 | 🤔 |
| P-521 / secp521r1 | 🤔 | 🤔 | 🤔 |
Encryption Support Matrix
| Algorithm/ECIES Variant | ECIES-MAC | ECIES-AEAD | ECIES-SYN |
|---|---|---|---|
| ChaCha20-Poly1305 | 🚫[^1]/🚫[^2] | 🚫[^1]/🚫[^2] | 🚫[^1]/🚫[^2] |
| XChaCha20-Poly1305 | 🚀 | 🚀 | 🚀 |
| AES-GCM | 📅 | 📅 | 📅 |
Authentication Support Matrix
| Algorithm/ECIES Variant | ECIES-MAC |
|---|---|
| HMAC-SHA256 | 🚀 |
| HMAC-SHA512 | 🤔 |
[^1]: ChaCha20 uses a 96-bit nonce, which when generated using a random function has an unsatisfactory risk of collision. XChaCha20 uses a 192-bit nonce where that is no longer an issue.
[^2]: Will not encourage using potentially weak encryption [^1] by implementing decryption for it
License
Licensed under either of:
at your option.
Contributing
All contributions are very appreciated.
- If you spot a mistake or a vulnerability in this crate or any of its dependencies please open an issue with the Fix algorithm template
- If you want to suggest adding support for a new algorithm, please use the Add algorithm template
- If you believe support for an algorithm should be deprecate, please use the Deprecate algorithm template
For all other issues, please try to include enough information so that it is possible to determine what to do or plan without having to ask too many follow-up questions.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.