Category Archives: Uncategorized

A few more notes regarding target collision resistant functions, following up from my $1000 competition announcement. Second preimage resistance There is a simple way to construct a secure TCR compression function given a second-preimage-resistant compression function—just generate a key which is the length of the input, and XOR the key with the input. So ifContinue reading “More thoughts on TCRs”

In my day job, I do cryptography for Android. I have a problem where I need to make some cryptography faster, and I’m setting up a $1000 competition funded from my own pocket for work towards the solution. On Android devices, key operating system components are stored in read-only partitions such as the /system partition.Continue reading “$1000 TCR hashing competition”

Credits: This way of looking at probability is due to Bruno de Finetti; this particular framing was taught to me by Andrew Critch. Out of the blue, you get the following email from me: Dear You: I extend to you, and you alone, a chance to take part in my free lottery. Please choose atContinue reading “Subjective probability”

7,000 children under five died of malnutrition today. It is said that Cato the Elder was so passionate about the losses in the Punic Wars, the threat of further aggression and the desire to impose a total punitive destruction to strike fear into all who might think to raise arms against Rome, that he finishedContinue reading “7,000 children under five died of malnutrition today”

I loved John Baez’s three-part system on large countable ordinals (1, 2, 3) but something nagged at me. It felt like a description of an algorithm in prose, and I feel like I don’t really understand an algorithm until I’ve implemented it. But what does it mean to implement an ordinal? I found a couple of answersContinue reading “Expressing computable ordinals as programs”

I’m writing this now because I anticipate linking to it over and over again; this fallacy isn’t going anywhere. Journalists have got very good at using the word “comparing” to turn the most innocuous statement into a gaffe, through a simple trick of equivocation. Most recently, Jeremy Corbyn is accused of “comparing” Israel and ISIS, butContinue reading ““Comparing””

EDIT 2017-10-28: DO NOT DO THIS! Dropbox have changed their API, and Netmemo has failed to update to use the new one. I emailed the developer and got no response. Don’t use Netmemo Plus. I want a button on my Android phone that drops voice notes into my GTD inbox. I want the raw audio, not theContinue reading “OBSOLETE: Voice notes for your Todoist inbox”

Superforecasting: The Art and Science of Prediction. Philip Tetlock and Dan Gardner. Crown; 352 pages; $8.14. Random House; £6.49. This book is essential reading for all thinking people. I’m not going to write a new review here—I think the existing reviews do it justice—I just wanted to add my voice to the recommendations. You don’t alreadyContinue reading ““Superforecasting””

Big life change ahead: in March, I, Jess, and our two cats will be renting out our London flat and moving to California’s San Francisco Bay Area for two years! I love the time I spend in the Bay and my wonderful friends there, and Jess and I have long said we wanted to spend some ofContinue reading “Moving to the Bay Area in March”

[Epistemic status: not serious. Mostly.] In my nightmares, even the rise of machine superintelligence isn’t enough to wipe out technical debt. Suppose the seed to the first true superintelligent agent is based on some fiendish numerical algorithm for supercomputers. Like so many fiendish numerical algorithms for supercomputers, the agent is written in FORTRAN to take advantageContinue reading “The technical debt of the millennia”