Searchable field-level encryption library for relational databases

v4.5.1 2023-10-28 10:16 UTC


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CipherSweet is a backend library developed by Paragon Initiative Enterprises for implementing searchable field-level encryption.

Requires PHP 8.1 or newer.

If you want to use CipherSweet on an older version of PHP (5.5+), use CipherSweet v3.

Before adding searchable encryption support to your project, make sure you understand the appropriate threat model for your use case. At a minimum, you will want your application and database server to be running on separate cloud instances / virtual machines. (Even better: Separate bare-metal hardware.)

CipherSweet is available under the very permissive ISC License which allows you to use CipherSweet in any of your PHP projects, commercial or noncommercial, open source or proprietary, at no cost to you.

CipherSweet Features at a Glance

  • Encryption that targets the 256-bit security level (using AEAD modes with extended nonces to minimize users' rekeying burden).
  • Compliance-Specific Protocol Support. Multiple backends to satisfy a diverse range of compliance requirements. More can be added as needed:
    • ModernCrypto uses libsodium, the de facto standard encryption library for software developers. Algorithm details.
    • FIPSCrypto only uses the cryptographic algorithms covered by the FIPS 140-2 recommendations to avoid auditing complexity. Algorithm details.
  • Key separation. Each column is encrypted with a different key, all of which are derived from your master encryption key using secure key-splitting algorithms.
  • Key management integration. CipherSweet supports integration with Key Management solutions for storing and retrieving the master encryption key.
  • Searchable Encryption. CipherSweet uses blind indexing with the fuzzier and Bloom filter strategies to allow fast ciphertext search with minimal data leakage.
    • Each blind index on each column uses a distinct key from your encryption key and each other blind index key.
    • This doesn't allow for LIKE operators or regular expression searching, but it does allow you to index transformations (e.g. substrings) of the plaintext, hashed under a distinct key.
  • Adaptability. CipherSweet has a database- and product-agnostic design, so it should be easy to write an adapter to use CipherSweet in any PHP-based software.
  • File/stream encryption. CipherSweet has an API for encrypting files (or other PHP streams) that provides authenticated encryption that defeats TOCTOU attacks with minimal overhead. Learn more.

Installing CipherSweet

Use Composer.

composer require paragonie/ciphersweet:^4

If you're intending to use CipherSweet on an older version of PHP, use the v3 branch:

composer require paragonie/ciphersweet:^3

Using CipherSweet

Please refer to the documentation to learn how to use CipherSweet.

Security experts may be interested in the security properties of our design.

Integration Support

Please feel free to create an issue if you'd like to integrate CipherSweet with your software.

CipherSweet in Other Languages

Why "CipherSweet"?

CipherSweet was originally intended for use in SuiteCRM (a fork of the SugarCRM Community Edition) and related products, although there is nothing preventing its use in other products.

Therefore, we opted for a pun on "ciphersuite" that pays homage to the open source heritage of the project we designed this library for.

If the wordplay is too heavy, feel free to just call it "Sweet", or juxtapose the two component nouns and call it "SweetCipher" in spoken conversation.

Support Contracts

If your company uses this library in their products or services, you may be interested in purchasing a support contract from Paragon Initiative Enterprises.