pybmdope 1.1.3

A Block Metadata-Driven Order-Preserving Encryption (BMDOPE)

pybmdope

BMDOPE (Block Metadata-Driven Order-Preserving Encryption) is a custom encryption library designed to process data securely while preserving the order of encrypted blocks.

Overview

BMDOPE is designed for scenarios where maintaining the order of encrypted data is critical, such as database indexing or range queries on encrypted data. It achieves this by encrypting data in blocks and using metadata to preserve the order of the blocks during encryption and decryption.

Disclaimer: The order-preserving properties of BMDOPE are currently available for numeric sorting only. Lexicographical ordering is supported only for data with fixed size.

Algorithm

1. Block-Based Encryption: Data is divided into fixed-size blocks, and each block is encrypted individually using a key.
2. Metadata Handling: Metadata is generated during encryption to store information about the length of each encrypted block. This metadata is encrypted separately to ensure security.
3. Order Preservation: The encryption algorithm ensures that the lexicographical order of the plaintext blocks is preserved in the encrypted blocks.
4. Key Management: The encryption key is reshuffled after processing each block to enhance security.

Use Cases

• Encrypted Databases: Perform range queries or sorting operations on encrypted data without decrypting it.
• Secure Indexing: Maintain the order of encrypted data for efficient indexing and retrieval.
• Data Transmission: Securely transmit ordered data while preserving its structure.
• Equality Checks: Use encrypt_bound to generate upper and lower bounds for equality checks. Since BMDOPE uses non-deterministic encryption (randomized IVs), the same plaintext does not produce the same ciphertext. By encrypting the bounds, you can perform range queries to match the encrypted data.

Installation

From PyPI

Install the package directly from PyPI:

pip install pybmdope

From Source

To install the package from the source, use:

pip install -e .

This will install the package in editable mode, allowing you to make changes to the source code and use them immediately.

Usage

Example

from pybmdope.bmdope import BMDOPE

# Initialize BMDOPE with generated key and IV
key = BMDOPE.generate_key()
bmdope = BMDOPE(key, iv)

# Data to encrypt
data = b"example data for encryption"

# Encrypt the data
encrypted_data = bmdope.encrypt(data)
print(f"Encrypted Data: {encrypted_data}")

# Decrypt the data
decrypted_data = bmdope.decrypt(encrypted_data)
print(f"Decrypted Data: {decrypted_data.decode('utf-8')}")

Testing

Unit tests are provided for all modules and integration. Run the tests using:

python -m unittest discover -s tests

TODO

• Replace binary string representation (e.g., b'1010101') with bitarray for improved performance and flexibility.

License

This project is licensed under the MIT License.