Security is one of the most important factors to consider when working with PDFs. Not only are PDFs vulnerable to viruses and malicious attacks, but there can  be serious consequences if they fall into the wrong hands. In this blog, we’ll discuss the major risk factors for PDFs when it comes to security and how developers can secure their PDF workflows effectively.  

Why PDF Security Is Harder Than It Looks 

The PDF format supports a wide range of features (including rich media like videos and clickable links), and that flexibility comes with complex implementations that expand the potential for security attacks.   PDFs are also supported across virtually every platform and continue to be the de-facto document format, making them an especially attractive target for attackers; a trend reinforced by ongoing standards work like ISO’s PDF 2.0.   Additionally, both by design and occasionally by accident, PDFs can act as delivery vehicles for malicious payloads, including JavaScript, multimedia content, fonts, and arbitrary file attachments. 

The illusion of “secure” PDFs 

It can be easy to have misplaced faith in native “security features” such as no-copy, no-print, and no-edit, but these controls often provide a false sense of protection. In practice, they are discretionary controls, meaning their enforcement is entirely up to the PDF viewer software, and not the document itself. A compliant viewer may choose to honor these restrictions, while another viewer, plug-in, or custom tool can simply ignore them. Since the permissions are not cryptographic or technically enforced at the file level, they can often be bypassed through alternative viewers, file conversions, screenshots, or basic PDF processing tools. As a result, these features are better understood as usage hints or policy signals rather than true security mechanisms, therefore they shouldn’t be relied on to protect sensitive or regulated content on their own. 

Common failure modes in enterprise PDF workflows: 

• Security and Compliance Failures: Inconsistent application of security, such as failing to properly redact sensitive information or failing to track an audit trail for document access, can lead to significant compliance risks. 
• "Half-Implementation" (a.k.a. Partial Adoption): Organizations may adopt new software but fail to fully train their staff, leading to resistance, abandonment, and/or the creation of unofficial workarounds.   

Threat Modeling PDF Workflows 

When threat modeling PDF workflows, these three areas help show where the risk actually lives and how it moves through your workflow. 

Threat actors and attack surfaces 

PDF workflows attract attackers because PDFs can hide malicious content. Any place where a PDF is uploaded, opened, processed, or rendered is part of the attack surface and should be treated as potentially unsafe. 

Client-side vs. server-side risks 

Handling PDFs on the client side puts the risk on users and their viewer software, which may not enforce security consistently. Server-side processing is easier to control, but it also means a single malicious file can impact entire backend systems if they aren’t well protected. 

Trust boundaries in PDF processing systems 

PDFs will cross multiple trust boundaries as they move from users to servers to other systems. At each step, the document should be treated as untrusted and validated before moving on.   

Integrating PDFs with Identity and Access Management (IAM) 

Using OAuth, SAML, and OpenID Connect with PDF workflows 

PDFs often live behind apps or APIs that already use OAuth, SAML, or OpenID Connect. Users must authenticate first, and PDFs are only created or delivered after their identity is verified. This keeps authentication in one place and aligned with enterprise SSO. 

Mapping user identity to document access 

Once a user is logged in, their role or group membership determines which PDFs they can access and what they can do with them. If that access changes, the system enforces it immediately, with no need to modify the PDF itself.  Enforcing access outside the PDF file itself  Real security happens before the PDF is ever downloaded. Applications, APIs, and storage systems control who can get the file, instead of relying on viewer-enforced PDF permissions. 

Patterns for integrating PDFs into enterprise IAM systems 

Common approaches include serving PDFs through authenticated APIs, generating them on demand after access checks, or storing them in secure repositories governed by IAM policies. In all of these cases, access is tied to the user’s identity, not the PDF file itself. 

Role-Based Access Control (RBAC) Inside PDFs 

Role-based access control (RBAC) is a model for authorizing end-user access to systems, applications, and data based on a user’s predefined role. In an RBAC system, an administrator assigns each individual user one or more roles. Each new role represents a set of permissions or privileges for the user.  For PDF workflows, this can involve:  Embedding security directly into the PDF file to restrict functionality regardless of where the file is stored.   Encrypting the document to require authentication, limiting actions to specific roles.  Allowing one role to read, another to comment, and restricting printing or copying for all users.  Dynamic Watermarking: Displaying user information (e.g., "Confidential - [Username]") based on the role of the user accessing the file. 

Secure PDF Encryption and Password Protection 

Though they commonly get lumped together, PDF encryption and password protection are not the same thing. Password protection controls access to the file (like a bouncer at a door), while encryption scrambles the data itself (like scrambling contents in a vault), making it unreadable without the correct key.   Password protection alone is weaker, as the data might be readable if the lock is bypassed; encryption provides stronger security by turning the data into gibberish to anyone without the decryption key, even if they get the file. 

PDF encryption standards (AES-128 vs AES-256) 

The choice between AES-128 and AES-256 encryption depends on balancing security requirements with performance considerations. Both of these are secure against brute force attacks with current technology, but 256-bit encryption offers a significantly higher security margin.  Regarding performance, AES-256 requires ~40% more processing power than AES-128 with its 14 rounds of processing versus 10.  On modern CPUs with built-in hardware acceleration (AES-NI), the performance overhead is often negligible for most applications. 

Note: Avoid weak or recoverable passwords 

This one speaks for itself – if you go the password-protection route, make sure you are using strong passwords for your documents that can’t be easily guessed or recovered.  

Programmatic Redaction of Sensitive Information at Scale 

There are major security risks associated with not correctly redacting information from your documents. Strictly enforced rules apply to documents that contain either classified or sensitive personal information and identifiers. Strict privacy laws apply in healthcare (Health Insurance Portability and Accountability Act), government (Freedom of Information Act and U.S. Federal Privacy Act), and other areas such as the legal and financial sectors. You risk exposure to potential litigation and fines if sensitive information is not fully removed before being released. It’s important to understand why redaction can fail and how to implement it properly. 

Why visual redaction fails  

Visual (image-based) redaction fails because it usually only masks sensitive information visually (placing a black box over text) rather than actually removing the underlying data. This allows hidden text to be copied, pasted, or recovered from files, particularly in PDFs, where improper techniques leave sensitive content accessible to users. 

Text-layer Redaction (“true” redaction) 

Text-layer redaction, or true redaction, permanently removes data (text, metadata, or images) from the document's structure, ensuring it can’t be recovered. Proper redaction should always involve scrubbing the underlying text layer to avoid leaks.  Learn more about proper redaction by reading PDF Redaction Fails and how to Avoid Them.

Best Practices for Securing PDFs with Datalogics 

By using our Adobe PDF Library SDK for encryption and permissions, you can rest assured that you’re getting the highest level of document security. Our software is rigorously tested by a highly knowledgeable support team to make sure this is the case. Here are some considerations as it pertains to using our software to secure your PDFs: 

Server-side processing patterns 

The safest way to secure PDFs with a Datalogics SDK is to do the work on the server, not on the client. You can apply encryption, redactions, and content cleanup before the file reaches a user, which keeps security consistent and avoids relying on viewer-enforced controls that can be ignored or bypassed.  

Secure deployment recommendations 

Treat PDF processing as a protected backend service. Keep the SDK behind authentication, restrict file and network access, and run it in isolated or containerized environments when possible. Regular updates and logging help ensure your PDF security stays effective as threats evolve. 

Additional PSA: As a company, we also have SOC 2 Type 2 certification, which positions us as a security-first business. To learn more about what that means, check out our blog, Datalogics Achieves SOC 2 Type 2 Certification that details the certification process.