Web Science and Digital Libraries Research Group

Figure 1: A web page from nasa.gov is archived  by Michael's Evil Wayback in July 2017. Figure 2: When visiting the same archived page in October 2017, we found that the content of the page has been tampered with.   The 2016 Survey of Web Archiving in the United States shows an increasing trend of using public and private web archives in addition to the Internet Archive (IA). Because of this tendency we should consider the question of validity of archived web pages deleivered by these archives.  Let us look at an example where the important web page https://climate.nasa.gov/vital-signs/carbon-dioxide/ , that keeps a record of the carbon dioxide (CO2) level in the Earth’s atmosphere, is captured by a private web archive “Michael’s Evil Wayback” on July 17, 2017 at 18:51 GMT. At this time, as Figure 1 shows, the CO2 was 406.31 ppm. When revisiting the same archived page in October 2017, we should be presented with the same content. Surpris...

The Memento Protocol provides a Memento-Datetime header indicating at what datetime a memento was captured by a given web archive. In most cases, this metadata sufficiently informs the user of when the given web resource existed. Even though it has been established in US courts that web archives can be used to legally establish that a given web resource existed at a given time , there is still potential to doubt this timestamp because the same web archive that provides the memento also provides its Memento-Datetime . Though not a replacement for Memento-Datetime,  trusted timestamping is the process that provides certainty of timestamps for content and can be used to provide additional data to alleviate this doubt. In this post, I examine different trusted timestamping methods. I start with some of the more traditional methods before discussing  OriginStamp , a solution by Gipp, Meuschke, and Gernandt that uses the Bitcoin blockchain for timestamping. Brief Crypto...