Encryption · Ruby
Encrypt a PDF in Ruby
Password-protect a PDF from Ruby with strong AES-256 encryption. rust-pdf applies standard-handler encryption at output, deriving keys and IVs from the operating system CSPRNG, and supports user and owner passwords plus permission flags.
Why Ruby needs this
Prawn generates beautiful PDFs but has no PDF/A, no digital signatures, no AES-256 and no PDF/UA, so the regulated features have simply been missing from Ruby.
Encryption keeps sensitive documents (statements, records, contracts) confidential and helps meet LGPD, GDPR and HIPAA obligations. rust-pdf implements AES-256 (V5/R6) directly, validated by qpdf for both user and owner passwords, and also supports AES-128 and legacy RC4.
- AES-256 (V5/R6) with keys and IVs from the OS CSPRNG, plus AES-128 and RC4 for legacy needs.
- Separate user and owner passwords, with a read-only permission mode.
- Encrypt new documents or an existing PDF you load and re-save.
Encrypt a PDF in Ruby with rust-pdf
Install the package, then call the same idiomatic API every rust-pdf binding shares. The snippet below is real Ruby code from the reference docs.
ed = RustPdf::EditableDoc.load_file("in.pdf")
ed.encrypt(method: RustPdf::Cipher::AES256, owner: "owner-secret", read_only: true)
ed.save("secured.pdf") # raises RustPdf::Error without an Encryption license
ed.closeRuby basic generation is free. Encryption is a corporate feature, unlocked by one offline license token. See pricing & licensing.
Full Ruby reference in the documentation.
Encryption in Ruby: FAQ
How strong is the encryption?
rust-pdf uses AES-256 with the modern V5/R6 security handler, the strongest standard PDF encryption. Keys, salts and IVs come from the operating system CSPRNG, so every encrypted file is unique. qpdf validates the output for both user and owner passwords.
What is the difference between user and owner passwords?
A user password is required to open the document. An owner password leaves the file openable but restricts actions such as printing or copying. You can set either or both, and enable a read-only permission mode.
Do I need a license to encrypt in Ruby?
Encryption is a corporate feature and needs an active license token. Basic generation in Ruby is free. The same offline token enables encryption in every language.
Encrypt a PDF in Ruby (AES-256)
One Rust core, the same output across every language. Prototype for free, license the corporate features when you ship.