A Fragile Watermarking Technique for Integrity Authentication of CSV-Files Using Invisible Line-Ending Control Characters

Every day, a growing amount of data, including audio, video, images, and plain text, is published and shared online. Facilitating its interoperable exchange, a range of standards and formats has emerged, establishing common ground. Among plain text formats, CSV prevails as one of the most used text formats. However, being a simplistic, plain text format, it lacks built-in security measures. Consequently, data users cannot authenticate the integrity of CSV texts they receive. A recognised method in research for ensuring text integrity is fragile watermarking. Accordingly, numerous watermarking techniques are available for tamper detection. However, many of these methods are either incompatible with the CSV format or visible to the human eye. To address these shortcomings, we propose a novel fragile watermarking technique for CSV files. Using invisible line-ending control characters, we are able to embed any byte-encodable information into a CSV cover text, making it truly imperceptible. We evaluated our technique by conducting three experiments to benchmark robustness, capacity and imperceptibility and comparing it with existing solutions. We found that our technique successfully achieves complete imperceptibility in all cases. However, a limited capacity and line-ending normalisation sensitivity must be considered when applying it.