Cipher is a flexible, extensible command-line application for encrypting and decrypting files using modern cryptographic standards, including support for post-quantum algorithms. It supports both symmetric and asymmetric encryption schemes, configurable password-based key derivation functions (KDFs), and profile-based parameter management.

Cipher securely encapsulates all necessary cryptographic material—including ciphertext, salt, nonces, and algorithm identifiers—into a single .enc or .sig file for reliable and portable decryption and verification. Key generation, storage, and verification are handled via RocksDB and Serde, with user-defined profiles simplifying cryptographic parameter reuse.

• Authenticated Encryption using AES-256-GCM and ChaCha20-Poly1305
• Known Answer Tests (KATs) for symmetric encryption schemes
• Password-based Key Derivation with Argon2 and PBKDF2
• User Profiles for storing cryptographic preferences (KDF parameters, AEAD choice)
• Asymmetric Encryption Support for RSA, ECC, Kyber, and Dilithium including:
  • Key generation
  • Encryption/decryption
  • Signing and verification
• Signed files are saved with a .sig extension
• Serde-powered serialization for user profiles and key storage
• Secure Key Storage using RocksDB with optional encryption of private keys
• Secure random salt and nonce generation
• Automatic zeroization of sensitive memory (e.g., keys, passwords)
• Password verification on entry to reduce human error
• Encrypted output stored in a single .enc file containing:
• Encrypted payload
• Algorithm identifiers
• Salt, nonce, and metadata

This project makes use of the following Rust crates:

• aes-gcm — Authenticated encryption (AES-256-GCM)
• chacha20poly1305 — Alternative AEAD cipher
• argon2 — Memory-hard password hashing and key derivation
• pbkdf2 — Password-based key derivation function
• hmac — HMAC construction for PBKDF2
• sha2 — SHA-2 hash functions
• aead — AEAD trait abstraction
• generic-array — Fixed-size arrays used in cryptographic types
• typenum — Type-level numbers used with generic-array
• rsa — RSA encryption, signing, and keypair generation
• p256 — NIST P-256 curve for ECC key exchange and signing
• elliptic-curve — ECC trait definitions and encoding support
• pqcrypto-kyber — Post-quantum Kyber encryption (Kyber512)
• pqcrypto-dilithium — Post-quantum Dilithium digital signatures (Dilithium2)
• pqcrypto-traits — Common trait interfaces for post-quantum schemes
• secrecy — Secret type wrappers for zeroization and memory safety
• zeroize — Secure memory zeroing for sensitive data
• serde — Serialization framework with derive support
• bincode — Binary serialization using Serde
• rocksdb — Persistent key-value database for profile and key storage
• lazy_static — Runtime-initialized global variables
• rpassword — Secure password input from the terminal
• clap — Command-line argument parsing with derive support
• rand — Random number generation
• rand_core — Core traits for RNGs
• directories — Cross-platform standard directories (config, data, cache)
• chrono — Date and time utilities

The cipher CLI tool provides a variety of commands to handle encryption, decryption, key management, and user profile customization.

• encrypt: Encrypt a file using symmetric (default) or asymmetric encryption. Supports profile-based parameter configuration, custom AEAD and KDF choices, and secure key handling.
• decrypt: Decrypt an encrypted .enc file back to its original format.

• keygen: Generate a new symmetric or asymmetric key pair (RSA or ECC). Can be associated with a profile for customized encryption settings.
• list-keys: Display all stored keys in the database.
• delete-key: Permanently delete a key by its ID.
• export-key: Export a public key as a .pub file for sharing or further use.
• import-key: Import a .pub file containing a public key for use in encryption or verification.

• profile: Update a user profile’s encryption parameters (e.g., kdf_id, aead_alg_id, memory_cost, etc.).
• list-profiles: Show all stored user profiles.

• sign: Digitally sign a file using a private key. The signature is saved as a .sig file.
• verify: Verify a signed file and optionally extract the original content.

Encrypts a file into a .enc file. Can be used for asymmetric encryption if an asymmetric key is provided. Optionally signes the ciphertext with a private key. If not key is provided it will default to symmetric encryption with a single use key.

Decrypts all .enc file. Verifies a signature if signed.

Updated profiles that contain default parameters for key derivation and symmetric encryption.

Lists all existing profiles.

Generates a new key or keypair.

Displays stored keys in the database. By default includes owned keys unless --unowned is specified.

Deletes a key by ID. Use --unowned if the key was imported and not locally generated.

If no flags are provided, all keys and profiles will be wiped by default.

Signs a file and creates a .sig file.

Verifies .sig files, can also strip the signature and header from the file.

Exports a public key associated with the given ID to a .pub file. If no name is provided, the key ID is used as the filename.

Imports a public key from a .pub file into the local key database. The file must have a .pub extension. Optionally assigns a user-defined name to the key.

The .enc file has two distinct variants, depending on whether symmetric or asymmetric encryption is used.

All fields are concatenated in the above order. The header is also used as AEAD associated data (AAD).

Unlike symmetric encryption, the ciphertext includes a key ID so the associated private key can be used.

The signature is generated over the header and file content, hashed and signed using the appropriate algorithm.

Encrypted files may be wrapped in a signature using the .enc extension. These files combine the encrypted content with a signature. These have the same external header as a .sig file with SIG2 as the magic bytes.

• Uses for password-based key derivation configurable parameters, 16-byte salt, 32-byte derived key.
• Symmetric encryption with a 12-byte nonce and AEAD for integrity and confidentiality.
• Asymmetric encryption schemes with optional signing for authenticity
• Digital signatures use asymmetric keys and sign both file metadata and contents.
• Passwords and plaintext key material are zeroized from memory after use.

• Key Derivation
  • Argon2id
  • PBKDF2-HMAC-SHA256
• Authenticated Symmetric Encryption and Decryption
  • AES-256-GCM
  • CHACHA20-POLY1305
• Asymmetric Encryption and Decryption
  • X25519 (ECIES-style hybrid encryption)
  • RSA PKCS1v1.5
  • Kyber512 (Post-quantum KEM, hybrid encryption)
• Asymmetric Signing and Verifying
  • ECDSA-P256 (SHA256)
  • RSA PKCS1v1.5
  • Dilithium2 (Post-quantum signature scheme)

• .enc files:
  • Symmetric mode stores: salt, KDF parameters, AEAD algorithm ID, and original filename (encrypted), and ciphertext (encrypted).
  • Asymmetric mode stores: asymmetric key type, symmetric AEAD ID, key ID, filename (encrypted) and ciphertext (encrypted).
• .sig files:
  • Include: magic bytes (SIG1), signing algorithm ID, key ID, original filename, original file length, original data, and the signature.
  • The private signing key is never stored, only the key ID is embedded in the file.
  • The signature covers both metadata and the full file content to prevent tampering.

Build production executable with:

cargo build --release

This project is licensed under the MIT License.