Digital document communication between an enterprise and a customer is becoming a primary form of communication rather than the traditional physical document communication. A PDF document, the most popular document format, provides an identical document layout regardless of OS or device and has a content integrity verification feature with a digital signature. However, it has a bad user experience, such as low readability on a mobile device. On the other hand, an HTML document has a weakness in verifying the content integrity even though it is the primary document format and provides a good user experience on mobile devices. There are certified document services using blockchain technology, but it is still vulnerable to verifying content integrity. Furthermore, research on the document HTML has proposed the trusted document generation technique by HTML conformance and digital signature; however, this research does not provide content delivery verification, and there is a file size overhead. In this paper, we have developed the chained document HTML by defining HTML conformance, digital signature, and blockchain technology. First, the chained document HTML has to embed all resources and does not allow loading content on-demand. Second, the file is signed by a digital signature, and the signature value is added in the file header. Lastly, the metadata to verify the content integrity is inserted in a blockchain node. We have created the chained document HTML generation and verification experiment environment by Ethereum and Python. We have confirmed that the chained document HTML provides content and delivery integrity verification in the research. We expect the chained document HTML will be widely used in document communication between an enterprise and a customer, especially if the document has sensitive personal information that might have a legal dispute.

A Web archive system is a traditional subject for preserving web content for the future and the importance is getting more significant due to the explosive growth of web content. The reference model for an open archival information system (OAIS) has been advising guidance for a long-term archiving system and most organizations that archive web content follow this guidance. In addition, the web archive (WARC) ISO standard is for web content archiving. However, there is no way to secure content integrity, and it is hard to identify the original. Because of limitations, a web archive system has a weakness against the dispute of content integrity. In this paper, we proposed the blockchain linked (BCLinked) web archiving system, which uses blockchain technology and an extended WARC field to keep a web content integrity metadata into a blockchain. Furthermore, we designed the BCLinked web archiving system, and we confirmed the proposed system secures content integrity through the experiment.

Electronic documents are becoming increasingly popular in various industries and sectors as they provide greater convenience and cost-efficiency than physical documents. PDF is a widely used format for creating and sharing electronic documents, while HTML is commonly used in mobile environments as the foundation for creating web pages displayed on mobile devices, such as smartphones and tablets. HTML is becoming a more critical document format as mobile environments have been raised as the primary communication channel nowadays. However, HTML does not have the standard content integrity feature, and an electronic document based on HTML consists of a set of related files. Therefore, it has a vulnerability in terms of reliable electronic documents. We have proposed Document HTML, a single independent file with extended meta tags, to be a reliable electronic document and Chained Document, a single independent file with a blockchain network to secure content integrity and delivery assurance. In this paper, we improved the definition of Document HTML and researched certified electronic document intermediaries. Additionally, we designed and validated the electronic document distribution service using Enhanced Document HTML for real usability. Moreover, we conducted experimental verification using a tax notification electronic document, which has one of the top distribution volumes in Korea, to confirm how Document HTML provides a content integrity verification feature. Document HTML can be used in an enterprise that must send a reliable electronic document to a customer with an electronic document delivery service provider.

A transaction document archive has been required by an enterprise company. However, the standard archive system consumes enormous processing time and storage because there are plenty of files depending on the number of customers. In this paper, we proposed ETD-archive (Enhanced Transaction Document archive) system which splits one PDF file which has all the customer document to shared resource and content and saves ETD-archive format to reduce total processing time and storage space. Our experiment has shown ETD-archive system reduces entire processing time and storage space efficiently.