> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/security/security.md). # Securing PDFs with Xamarin library Learn how to secure and read documents with encryption using PDFSecure, a command-line tool for adding password protection and adjusting permissions on PDFs. Find out more about password protecting PD Security on a PDF document protects the content from unauthorized access like copying or printing. PDF documents can be secured and encrypted using various encryption schemes. Control over document security in Apryse SDK is performed through *security handlers*. Security handlers perform user authorization and sets various permissions over PDF documents. Apryse SDK benefits include: * Support for Standard PDF security handler (40 and 128 bit RC4 encryption) * Support for 128 and 256 bit AES (Advanced Encryption Standard) encryption * Support for custom security handlers * Support for Crypt encryption filters * Set or modify security permissions associated with a document * Remove encryption from existing PDF documents * Powerful extension mechanism allowing for seamless integration with client applications ## Get started [Securing a document with encryption](/xamarin/security/encrypt.md) To secure a document with password protection and adjusting permissions on the document. [Reading a document with encryption](/xamarin/security/decrypt.md) To read a document with password protection without user feedback. ## Tools & Utilities [PDFSecure](/cli/pdfsecure/pdf-secure.md) A command-line tool that can be used for adding, removing, or changing security settings on existing PDF documents or whole directories of documents. ## Related blogs [How to Password Protect a PDF](https://apryse.com/blog/pdf-access-control-with-passwords) - 8/22/24 --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.apryse.com/xamarin/security/security.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.