Picocrypt -

No install, no dependencies, completely open source (MIT License), and only 2,000 lines of code. The Cryptography Behind the Curtain Picocrypt does not invent new cryptography (a cardinal sin). Instead, it selects the absolute best primitives and glues them together perfectly.

When a piece of software contains hundreds of thousands of lines of code, it inevitably contains bugs, backdoors, or unintended vulnerabilities. picocrypt

If you are a journalist protecting sources, a lawyer safeguarding client files, or just a parent securing your scanned Social Security cards, No install, no dependencies, completely open source (MIT