Archives – ross spencer :: exponentialdecay.digipres

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.

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.

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?

Cat's Meow from the Offner Dynograph EEG

What will you bitflip today?

I want to let you into a secret: I enjoy corruption. Corrupting digital objects leads to undefined behavior (C++’s definition is fun). And flipping bits in objects can tell us something both about the fragility, and robustness of our digital files and the applications that work with them.

I had a pull-request for bitflip accepted the other day. Bitflip is by Antoine Grondin and is a simple utility for flipping bits in digital files. I wrote in my COPTR entry for it that it reminds me of shotGun by Manfred Thaller. The utility is exceptionally easy to use (and of course update and maintain written in Golang) and has some nice features for flipping individual bits or a uniform percentage of bits across a digital file.

My pull-request was a simple one updating Goreleaser and its GitHub workflow to provide binaries for Windows and FreeBSD. I only needed to use Windows for a short amount of time thankfully, but it’s an environment I believe is prevalent for a lot of digital preservationists in corporate IT environments.

Bitflip is a useful utility to improve your testing of digital preservation systems, or simply for outreach, but let’s have a quick look at it in action.

Tyler's Halloween Matryoshka Dolls represent the internal complexities of container file formats. The dolls here have formats attached to them representing different ways they might be nested, with ZIP and OLE2 being the primary containers that can be handled in DROID and Siegfried at present.

A year in file formats 2024

A great write up from Francesca at TNA about the past year for PRONOM via Georgia at the OPF.

It’s great to see the continuing work including vital translation of guides into other languages. Francesca includes a couple of shout outs to some pieces I have contributed in my spare time this year; including a collaborative workshop with Francesca, David, and Tyler at iPRES2024.

A tree at sunset photographed from the train on the Bodendsee in Southern Germany

Versioning as memory?

So, it turns out my theme of the moment is code hygiene (or maybe memory?).

Today I am thinking about versioning, especially in relation to its impact on digital preservation; both software preservation and the impact of versions on long-term preservation efforts in other contexts.