ross spencer :: exponentialdecay.digipres :: blog

Image shows two layered waveforms, one a corrupt waveform and the other a good original. The corrupt form is in red and the uncorrupt one is green.

Revisiting bsdiff as a tool for digital preservation

I introduced bsdiff in a blog in 2014. bsdiff compares the differences between two files, e.g. broken_file_a and corrected_file_b and creates a patch that can be applied to broken_file_a to generate a byte-for-byte match for corrected_file_b.

On the face of it, in an archive, we probably only care about corrected_file_2 and so why would we care about a technology that patches a broken file?

In all of the use-cases we can imagine the primary reasons are cost savings and removing redundancy in file storage or transmission of digital information. In one very special case we can record the difference between broken_file_a and corrected_file_b and give users a totally objective method of recreating corrected_file_b from broken_file_a providing 100% verifiable proof of the migration pathway taken between the two files.

Turning NASA Wake-up Calls into data

For a while back then I was into space flight again. Scientists, science communicators, and engineers were all excited for a new era of rocket launches and the potential unification of the human race as we look towards the future.

During that time I discovered Colin Fries’ work in the NASA History Division to document all NASA “Wake-up calls”. A wake-up call is simply a piece of music used to wake astronauts on missions, a different piece of music, daily, for the duration of the flight.

Take, for example, the last Space Shuttle mission (Space Transportation System) STS-135; it was in flight for 13 days, and the wake-up call on day one was Coldplay’s Viva la Vida, while on day 13 it was Kate Smith singing God Bless America.

As a huge music buff who has the radio or music television on 18 hours a day, I really wanted to delve into this further. While Colin’s work is great, it’s just a PDF file (@wtfpdf). A PDF is not an ideal file format for querying data and gleaning new insights. So, while I wanted to explore it, I first decided to turn it into a true dataset. The result was a set of resources, a website, a JSON, a CSV, and an SQLite database which are each more functional and more maintainable over time.

Lets take a look at the results and https://nasawakeupcalls.github.io below!

Crayola's 1997 Techno Brite crayon set with color names created to market the Crayola website, including names featured here such as World Wide Web Yellow, Point and Click Green, and Cyber Space Orange

Looking after your URLs: tikalinkextract eight years on

We might not have a second life, but what if I told you there was a second internet? Not the deep web, but another web that we engage with nearly every day?

Think about it, that QR code you scanned for more information? That payment link you followed on your electricity bill? The website you’re told to visit at the end of a television ad?

The antipodes of the internet are these terminal endpoints, material and not necessarily material objects that represent the end of the freely navigable web — the QR code on a concert poster is the web printed onto the physical world. There is every chance it will be scanned and followed by someone from a mobile device, but it’s a transient object, something that will exist for a short amount of time, and then disappear into the palimpsest of the poster board or wall it was pasted on until it eventually disappears.

This is part of the materiality of the internet that has long fascinated me. Perhaps it comes from being a student of material culture, but if we look around, we see the Internet everywhere!

An slide excerpt from my presentation Declarative Programming for Digital Preservationists showing how network effect can be embraced and side-effects are reduced in the declarative paradigm.

Declarative programming for Digital Preservationists @ NTTW8

Just released on the No Time to Wait (NTTW) YouTube channel is my presentation from NTTW8 in Karlsruhe, Germany. (Slides also available here).

The presentation follows up on my proposal for iPRES 2024 and allowed me to present parts of what was, in the end, a pretty significant paper (in terms of word count).

Some of my reflections on the presentation are below.

A screenshot of a file format (fmt/983) in 0xffae. The title 0xffae sits over the top of the original image.

File formats as Emoji: 0xffae

tldr: https://emoji.exponentialdecay.co.uk

File Formats As Emoji (0xFFAE or 0xffae) might be my most random file format hack yet. Indeed, it is a random page generator! But it generates random pages of file formats represented as Emoji.

The idea came in 2016 with radare releasing a new version that supported an emoji hexdump. I wondered whether I could do something fun combining file formats and the radare output to create a web-page.

Along came a spare moment one weekend, some pyscript, and bit of sqlite, et voilà. File Formats as Emoji (0xFFAE) was made a reality.

Image of the foundations of a new building being erected in Wellington New Zealand, circa 2017.

File format building blocks: primitives in digital preservation

A primitive in software development can be described as:

a fundamental data type or code that can be used to build more complex software programs or interfaces.

– via https://www.capterra.com/glossary/primitive/ (also Wiki: language primitives)

Like bricks and mortar in the building industry, or oil and acrylic for a painter, a primitive helps a software developer to create increasingly more complex software, from your shell scripts, to entire digital preservation systems.

Primitives also help us to create file formats, as we’ve seen with the Eyeglass example I have presented previously, the file format is at its most fundamental level a representation of a data structure as a binary stream, that can be read out of the data structure onto disk, and likewise from disk to a data structure from code.

For the file format developer we have at our disposal all of the primitives that the software developer has, and like them, we also have “file formats” (as we tend to understand them in digital preservation terms) that serve as our primitives as well.

Image of a children's learn to code textbook by Usborne Books. The page shows a snippet from a computer game in BASIC called "Escape". The illustration is of three menacing looking Cyborgs.

Informed consent: considering steganographic techniques to fingerprint Generative AI output

Artificial intelligence (AI) is a polarizing topic. For every reasoned assessment of the technology and its potential to make some of our smaller, onerous, or more repetitive tasks easier, there are probably 100 reactive pieces predicting some radical overhaul of societal norms, from the service industry receiving new intakes of out of work software developers to laypeople taking on roles traditionally occupied by those of a college education, if they just start “asking their AI the right questions“ ¯\_(ツ)_/¯

The amount of AI-propaganda is draining, and the reaction is often spread across the board too, some cheer leading, some decrying, plenty taking their time to offer skilled and nuanced rebuttals, or suggestions for improvements.

I find myself largely trying to stay out of the conversations. A lot like blockchain conversations 8 years ago, it will take another half decade for the hype-cycle to plateau for us to see where it can truly complement our work.

One part of the conversation that is increasingly harder to ignore, is being informed about when AI has been used in the generation of text or images. It is the property of knowing, or having the tools to know is what I feel is the most important.

How can we be better informed about when AI is used, so that we are better prepared as consumers, to receive and understand content?

In this blog I want to explore the potential for steganography techniques to be used in the output of AI to fingerprint content and provide a way for front-end mechanisms to identify it, as we might file formats using magic numbers, so that users can be given the chance of informed consent: the opportunity to opt-in or out of whether we engage with AI content or not.

Animated GIF of various corrupted frames from Johan's Y2K cover.

The sensitivity index: Corrupting Y2K

In December I asked “What will you bitflip today?” Not long after, Johan’s (@bitsgalore) Digtial Dark Age Crew released its long lost hidden single Y2K — well, I couldn’t resist corrupting it.

Fixity is an interesting property enabled by digital technologies. Checksums allow us to demonstrate mathematically that a file has not been changed. An often cited definition of fixity is:

Fixity, in the preservation sense, means the assurance that a digital file has remained unchanged, i.e. fixed — Bailey (2014)

It’s very much linked to the concept of integrity. A UNESCO definition of which:

The state of being whole, uncorrupted and free of unauthorized and undocumented changes.

Integrity is massively important at this time in history. It gives us the guarantees we need that digital objects we work with aren’t harboring their own sinister secrets in the form of malware and other potentially damaging payloads.

These values are contingent on bit-level preservation, the field of digital preservation largely assumes this; that we will be able to look after our content without losing information. As feasible as this may be these days, what happens if we lose some information? Where does authenticity come into play?

Through corrupting Y2K, I took time to reflect on integrity versus authenticity, as well as create some interesting glitched outputs. I also uncovered what may be the first audio that reveals what the Millennium Bug itself may have sounded like! Keen to hear it? Read on to find out more.

"Bei der Buche", a landscape architectural installation by landscape architect and photographer Karina Raeck. Created in 1993 in the Wartberg area north-east of Stuttgart.

wikidata + mediawiki = wikidata + provenance == wikiprov

Today I want to showcase a Wikidata proof of concept that I developed as part of my work integrating Siegfried and Wikidata.

That work is wikiprov a utility to augment Wikidata results in JSON with the Wikidata revision history.

For siegfried it means that we can showcase the source of the results being returned by an identification without having to go directly back to Wikidata, this might mean more exposure for individuals contributing to Wikidata. We also provide access to a standard permalink where records contributing to a format identification are fixed at their last edit. Because Wikidata is more mutable than a resource like PRONOM this gives us the best chance of understanding differences in results if we are comparing siegfried+Wikidata results side-by-side.

I am interested to hear your thoughts on the results of the work. Lets go into more detail below.

René Magritte's The Lovers, Paris 1928 (Photographed at MoMA, NYC in 2017

Unrealized ideas: Unintentional Secrecy in the Era of Openness

Tyler recently posted this quote:

“History unprocessed is opportunity unrealized”

It reminds me of an unrealized article I wasn’t able to get written and into the wild, but it’s an important thought I would like to share nonetheless.

Proposed for James Lowry’s ACARM Symposium in 2015, I wanted to discuss when government is unable to adequately fund day-to-day effort, and research and development in the archive sector, leading to inefficient and potentially ineffective processing pipelines for records of archival value accessioned from government agencies and commissions.

It was just an abstract, but maybe folks have thoughts about this? Have we moved on since the early to mid 2010’s? What modern metrics do we have available to us today to see the progress? What does the advent of the new US administration mean for issues like this? As well as increasing worldwide authoritarianism?

Journal of a Digital Preservation Quartermaster

Revisiting bsdiff as a tool for digital preservation

Turning NASA Wake-up Calls into data

Looking after your URLs: tikalinkextract eight years on

Declarative programming for Digital Preservationists @ NTTW8

File formats as Emoji: 0xffae

File format building blocks: primitives in digital preservation

Informed consent: considering steganographic techniques to fingerprint Generative AI output

The sensitivity index: Corrupting Y2K

wikidata + mediawiki = wikidata + provenance == wikiprov

Unrealized ideas: Unintentional Secrecy in the Era of Openness

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