Text Redaction Tools: 3 Solutions Compared


You may have read that LibreOffice (or NeoOffice, ApacheOffice, OpenOffice or even the original StarOffice) has recently released its latest version 6.3 to the public.  The free Office alternative offers a suite of office application components that deliver full file compatibility with Microsoft Office. 

This latest version release delivers some significant performance enhancements as well as several additional features, including text redaction. Redaction or ‘black boxing’ as it is also known, is where a document has sensitive information removed as the reader is not authorized to see it. In many legal cases, documents that are released to the public are redacted to prevent certain sensitive information from being exposed to the public domain.

In today’s world of digital collaboration and ever-increasing data protection and privacy laws, the true value of redaction is now coming to the fore. Not just within the legal sector, but as a critical tool for today’s modern information security strategy.

However, understanding what redaction options available, including how they work, is crucial to determine if the technology will indeed be effective and beneficial to an organization.  Accordingly, we’ve provided an overview of three redaction solutions below. 

  1. 1) Redaction in LibreOffice

In LibreOffice, the built-in redaction feature works by exporting the document to LibreOffice Draw. In Draw, a Redaction Toolbar lets you draw rectangles over the sensitive pieces of information, before exporting the result as a PDF. It works, and for a quick one-off is probably adequate, but there are several issues with this functionality. 

Here’s the 3 major downsides to this approach:

  • It’s manual and clunky:  the user must use multiple applications and draw boxes around text to redact it.

  • It’s user driven:  the user must choose what to redact and when. Remember, most security violations are caused by human error. If just one user misses one piece of sensitive information and its shared or published, then what was supposed to be ‘secret’ is no longer secret.

  • It’s not collaborative:  it saves the file as a PDF with bitmap images which is not a friendly way to collaborate on a document (you can save it as a document with the shapes over the text – but this still enables copy and paste of the text underneath… which makes the redaction exercise pointless).

  1. 2 ) Redaction in Microsoft Office

So, how does the redaction component work in Microsoft Office? There are two ways. Either the user goes through each document manually to replace the sensitive text with a series of “X” characters or integrate a 3rd party tool (but now you have the additional charge per user). 

Here’s the 3 major downsides to this approach:

  • It’s manual:  the user must manually go through each document to redact the sensitive information.

  • It’s user driven:  as per LibreOffice, redaction in Microsoft Office relies upon the user to leverage the redaction functionality as well as making the right decision as to what text to redact and when. This puts the organization at risk of accidental or inadvertent data breach should the user “miss” redacting some sensitive information or forget to redact all together.

  • It doesn’t work for all file types:  the redaction functionality only works on text in basic Office file types (e.g. Word and Excel), it doesn’t work on images files such as PDF, JPG, BMP etc.


  1. 3) Redaction in Clearswift Gateway Solutions

Clearswift developed and delivered its data redaction functionality more than five years ago. By working with its customers and understanding their requirements, a reliable solution was developed, and the technology built into all its core email and web solutions. The redaction piece can also be added on to most of today’s email and web security products quickly and easily to augment their functionality. 

Here’s the 3 major advantages to the Clearswift approach to redaction:

  • It’s automated and occurs in real-time:  policies can be set and peered across numerous digital collaboration channels for consistent discovery of words, phrases and tokens, ensuring all sensitive information is detected and redacted automatically. This takes the decision to redact away from the user and bases the actions on company policy.

  • It’s applied to a wide variety of file types:  Clearswift’s redaction will work on most of today’s digital file types including Microsoft Office, Libre Office, PDF and increasingly important, images such as screenshots (JPG, BMP etc) and multi-function printer scanned PDFs. 

  • Education and security evolution:  real-time reporting highlights policy violations that can be used to both educate staff and evolve security policies and processes. If people are sending information to unauthorized recipients – whether accidentally or inadvertently  – while the system will correct the issue to prevent a data breach, the sender needs to be educated as to what they did wrong and given direction as to how to avoid the situation occurring again.

The ultimate redaction solution is about protecting sensitive information, enabling continuous collaboration and ensuring only authorized information is shared. But to be worthwhile, redaction needs to be automated, work on all the file types used across the organization and consistently protect all communication channels. Finally, as with any security solution, it needs to be as easy to use and manage within the organization to minimize operational overhead. 

Contact the Clearswift team to learn more about redaction.

Additional Information:

Clearswift Adaptive Redaction

Clearswift Data Redaction

Clearswift SECURE Email Gateway

Clearswift SECURE Web Gateway

PCI Compliance Best Practice Guide: Redacting Credit Card Information


*** This is a Security Bloggers Network syndicated blog from Clearswift Blog authored by James.Cox. Read the original post at: