Apparent Anonymization with Document Editors
Companies are increasingly using free anonymization tools, but many of these only visually mask data instead of actually removing it. In this article, we discuss how easily hidden information can be uncovered, which poses significant risks.
Online Tools Applying Layers – A Real Risk of Data Recovery
In today’s experiment, we anonymized a petition using an online editor that applies graphical masking layers. At first glance, the document looked properly redacted. However, using a PDF reader equipped with text extraction capabilities, we managed to recover the hidden information. Then, using another online editor, we completely removed the masking layers, revealing the original content once again.
This experiment clearly demonstrates that not all anonymization methods are effective. In fact, data might still be accessible despite being visually obscured.
Original Version of the Petition
In this article on the risks of traditional anonymization methods, you can find the original petition: Read more!
Anonymized Version of the Petition
Petition redacted with free document editing software.
Remaining OCR Risks
In document editing tools, applied layers only visually cover previously visible text. Nevertheless, thanks to search functions or text-to-speech features, sensitive data such as names, surnames, or phone numbers often remain accessible. This is because they are still stored in the document’s structure, making recovery possible. Furthermore, the screenshot below provides a visual representation of this process.
Text Editing Tools
In free online editing tools, simply opening the document and selecting the text beneath the masking layer frequently makes it visible without needing to remove the layer. For instance, in our case, clicking on the text under a white rectangle was sufficient to reveal what should have been hidden. Moreover, in some cases, we even managed to completely remove the masking, restoring the document to its original state. Below is a screenshot that illustrates this process.
Consequences and Employee Unawareness
Many companies and institutions unknowingly expose confidential data by relying on ineffective anonymization methods. As a result, those responsible for data management often assume that applying masking layers in PDF editors or basic online tools is enough to securely hide sensitive content. However, employees who perform these operations daily might not be aware that text covered by a rectangle or another graphic element remains stored in the file’s structure and is easily retrievable.
Our experiment shows that the consequences of a false sense of security in text editing tools can be severe. Moreover, even simple steps can easily expose sensitive details. In addition, removing the masking layer was surprisingly easy, which in turn restored the original content.
The consequences of such oversights can be severe, ranging from violations of data protection regulations to leaks of confidential corporate information. Therefore, it is crucial for both management and employees to recognize these risks. Additionally, they should adopt anonymization methods that permanently remove data rather than merely masking it.
How to Safely Anonymize This Document?
To safely anonymize this document, it is best to use dedicated anonymization software such as Bluur. This tool ensures irreversible anonymization, effectively removing all personal and sensitive data while adhering to the highest security standards. By utilizing advanced algorithms, Bluur guarantees that the document can be safely shared and stored without the risk of privacy breaches. This solution is ideal for companies and institutions that prioritize data protection in compliance with regulations such as the GDPR.
