Archives for category: Science

David Chaum introduced blind signatures almost four decades ago [1], as the fundamental building block to implement a form of untraceable digital cash. His proposal was to represent each digital coin as a unique serial number blindly signed by the issuing bank. The unique serial number embedded in the coin would prevent double spending, while the blind signature over the coin would guarantee both untraceability (by not knowing which coin was signed) and unforgeability (by signing the coins in the first place). Unfortunately, the way Chaum explained the blindness property has somewhat obscured the fact that it actually has two different faces.

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The Netherlands uses a nationwide, smart card based, public transport ticketing system called “OV chipkaart“. This system logs all trips made by all people travelling by public transportation in the Netherlands in one central database. This is even the case for the so called anonymous OV chipcard, which gave rise to a court case recently asking the judge to order the Dutch data protection authority to start enforcing the GDPR. And that in turn got me thinking about how to implement public transport ticketing in a privacy friendly way.

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Suppose you want to go to the movies tonight. Or perhaps your favourite band is coming to town. To secure a ticket for the event, you decide to buy one online. You select the event details, make sure you selected the right date and time, choose the e-ticket option (provided the shop even offers alternative delivery options), and you are ready to proceed to checkout and pay.

But wait.

Somewhere along the ordering process you are required to sign in to your account at the online ticket shop. If you don’t have an account yet, you’ll have to create one, and you will probably be asked to provide your full name, home address, phone number and email address. In some cases you will have to provide more information, like your age, and perhaps your credit card number (for future purchases). Doesn’t that surprise you? No? Perhaps you are so used to it now, so conditioned to it, that you no longer really notice this identification step, let alone question it. Apparently you have bought into the myth that ‘they’ always need to know who you are. But do they, really?

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In 2016, the Nine Dots Prize was awarded for the first time, to James Williams. His prize? The opportunity to develop his 3.000 word idea into a full-length book: ‘Stand Out of Our Light: Freedom and Resistance in the Attention Economy’ (available from Cambridge University Press as open access). This is a review of that book.

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The push for open access to scientific publications is finally getting traction. For example, Plan S, backed by mostly European institutes funding scientific research, was launched in September last year. But I really worry about the direction we are heading. Current proposals essentially maintain the status quo and keep the huge profits of the publishers intact. The only change is that instead of libraries paying for subscriptions, authors now pay for publishing their papers. This is problematic for several reasons, to be explained in this post, and hence not a solution. Instead we should strive for a model where both the publishing of scientific papers by authors and the access to those papers by anyone in the world should be open to and free for all. In other words: open access should be free for both authors and their readers.

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Here is an attempt to give a general definition of a distributed ledger, trying to encompass most existing forms of blockchains and distributed ledgers, making their (theoretical) properties and underlying assumptions explicit. We start with a long definition, following with a shorter summary. Comments and suggestions for improvement are more than welcome.

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(This is a provocation for the workshop “10 Years Of Profiling The European Citizen”, June 12-13, 2018, Brussels, for the panel on “Transparency theory for data driven decision making”)


Perhaps Louis Brandeis can be considered the father of all transparency theory because of this famous quote of his:

“Publicity is justly commended as a remedy for social and industrial diseases. Sunlight is said to be the best of disinfectants; electric light the most efficient policeman.”

Indeed transparency is commonly seen as an important tool to counter the ill effects of automated, data driven, decision making.

But I cannot fail to wonder: what if the sun does not shine?…. Wouldn’t that render transparency useless? Indeed, wouldn’t that turn transparency into a perfect cover-up, allowing organisations to hide in plain sight, pretending not to be engaged in any nefarious activities?

Below I will discuss the limits of transparency and discuss six different reasons why transparency by itself is not enough. First, transparency only helps if there are enough experts to verify the information provided. Second, transparency is useless if subjects do not have agency and have no meaningful way to challenge a decision. Third, transparency requirements may be subverted or sidestepped by providing information in an opaque way. Fourth, certain decision making process are hard to explain to begin with. Fifth, a decision may be hard to challenge because scrutinising the decision requires domain expertise and sufficient (computational) resources. And finally, transparency may conflict with business or government interests.

These six arguments are presented in detail below, followed by a brief conclusion.

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