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Jasvir Nagra

@jasvir

Advisor & builder. Formerly security @dropbox, product @instart & @google, authored Surreptitious Software, TL for Caja. I love good food, fine wine & great JS.

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02.05.2023
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Latest posts by Jasvir Nagra @jasvir

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Hogwarts: Names & Delegation If part one was the theory, this one is wizardry. And yes: this post is going to be very Hogwarts-focused, partly because Hogwarts is weirdly good for threat modeling, and partly because I am a fan of...

So I like HP. A lot. I think about Hogwarts as a security thingy & honestly it holds up alarmingly well: Polyjuice breaks auth, the Trace is noisy telemetry, and the Fidelius Charm is basically ocaps with some extra drama.

www.linkedin.com/pulse/hogwar...

24.02.2026 20:31 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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Names Are Handles There are only two hard things in Computer Science: cache invalidation, naming things, and off-by-one errors. This old joke highlights that naming stuff is notoriously tricky β€” and not just for progra...

I think about names a lot.

Names aren’t labels...they’re handles. Human names are messy & relational, myths treat true names as power, and ocap security makes it literal: hold the handle (key/token/secret URL) β†’ you have power.

www.linkedin.com/pulse/names-...

17.02.2026 19:27 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

subgraph isomorphism is in NP - that feels like something!

30.01.2026 15:04 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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I Am Not U or I β‰  U The sequel to Quines Previously, we have played with Quines: programs that print their own source code. Self-reproduction.

Quines say "say me"
Inequ say "see me"

Self-recognizing programs that read program text & ask: "Is that… me?"

Starts as byte checks & spirals into mirror tests, regex narcissism & CS slamming an UNDECIDABLE stamp on dreams.

www.linkedin.com/pulse/i-am-u...

#RecursiveRhymesOnReason

27.01.2026 22:34 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Ezra Pounds Forests In a Station of the Metro with Perl and Unicode Last week I argued that translation isn’t moving words from one language to another β€” it’s swapping interpreters, and admitting you can’t keep everythin...

I translated Ezra Pound’s 14-word metro poem into a Perl one-liner with Unicode emojiβ€”and it literally prints trees: a tiny experiment in what translation really preserves (spoiler: not the words).

www.linkedin.com/pulse/ezra-p...

#RecursiveRhymesOnReason

20.01.2026 20:46 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
National Nothing Day - Wikipedia

I didn't realize today is National Nothing Day. Unfortunately, I didn't celebrate it.

en.wikipedia.org/wiki/Nationa...

17.01.2026 01:36 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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Untranslatable Lessons from what it means to translate a nursery rhyme into JavaScript β€œPoetry is what gets lost in translation” β€” Robert Frost This quote is widely attributed to Robert Frost but the attribution its...

I translated a nursery rhyme into JS & learnt with translating poems, you gotta choose what is load-bearing.

From nonsense poems to haiku constraints to code-poetry...

Translation: It's staged word magic + citations.

Enjoy!

www.linkedin.com/pulse/untran...

#RecursiveRhymesOnReason

14.01.2026 02:53 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
Humpty Dumpty - JSFiddle - Code Playground JSFiddle - Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle.

Fun with JS

const _=new Proxy([],{get:(b,k)=>k=="_"?(console.log(b.join` `),b.length=0,_):(b.push(k),_)})

_.Humpty.Dumpty.sat.on.a.wall._
_.Humpty.Dumpty.had.a.great.fall._
_.All.the.kings.horses.and.all.the.kings.men._
_.could.not.put.Humpty.Dumpty.together.again._

jsfiddle.net/jnagra/vg79m...

07.01.2026 21:39 πŸ‘ 2 πŸ” 1 πŸ’¬ 0 πŸ“Œ 0
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Know It All: A Tour of Knowledge’s Limits There are questions we don’t know yet, questions we can’t know ever, and questions where the answer literally can’t fit inside the…

Sometimes we don’t know yet, sometimes the answer doesn’t fit in the universe & sometimes we can’t ever know.

Chaos, quantum dice, uncomputable monsters, GΓΆdel’s ceiling - knowledge has weirdly beautiful limits.

I wrote on things we cannot know: medium.com/@jasvir/know...

Enjoy!

06.01.2026 22:13 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Do you think Pavlov's dogs like pavlova? Or are they just conditioned to think they do?

25.12.2025 19:50 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Ok this meteor shower is gorgeous. I find it oddly romantic that a comet exploded around this part of the solar system ages ago and now once a year in December as earth blazes through it, we get shiny pretty things in the sky.

#GeminidMeteorShower

14.12.2025 08:36 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

A joke for vexillologists - Is the US nervous about China because it's a red flag? 🚩

01.12.2025 17:38 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

The sky is solid uniform white today! It's like they forgot to finish rendering the screen in a game.

30.11.2025 18:56 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

rorohiko:song jas$ time say "aioli"

real 0m1.024s
user 0m0.115s
sys 0m0.047s
rorohiko:song jas$

29.11.2025 18:00 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

I think you're right!

Currently my machine is saying outloud every word in /usr/share...words and timing it. I just need some consistent pronunciation - else I'll fool myself by saying some words faster than others.

29.11.2025 17:59 πŸ‘ 2 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

"Strengths faded after six long months."
Time: 2.825s | Length: 38 | Time per char: .0743 s/char

"Sixths of their strengths were gone."
Time: 2.183s | Length: 36 | Time per char: .0606 s/char

"They survived on crisps and squirrel strength."
Time: 2.817s | Length: 46 | Time per char: .0612 s/char

29.11.2025 17:24 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Oh the sentence has to be grammatically correct ofcourse.

29.11.2025 17:14 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

This is my best attempt so far:

rorohiko:song jas$ time say Squirrels hid crisps through sixteen long months.

real 0m3.150s
user 0m0.159s
sys 0m0.112s
rorohiko:song jas$

29.11.2025 17:13 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

In case you're foolish enough to be nerdsniped, there is presumably the shortest sentence that takes the longest to say clearly... what is that sentence?

29.11.2025 17:12 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Soooo... I had a weird dream about a silly made up puzzle then woke at 5am trying to think of ways to solve it. And have now spent 4hrs on it.

How's your Saturday?

29.11.2025 17:08 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

You joke but you know, weirdly, in the limited world of programming languages - this is a large part of the work you've done fixing JS - making the core make consequences be intentional. :p

29.11.2025 06:42 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Mostly the summaries @gothamchess.bsky.social makes.

27.11.2025 19:50 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Thanksgiving feels like a good day to think about Dining Philosophers.

27.11.2025 17:22 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

I think watching the World Cup Chess this year is the first time I've remembered the passionate enthusiasm sports fans have about about whatever their game is since maybe the 1990 rugby 7s.

It's so crazy all over the place. So fun!

24.11.2025 19:51 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

What's the fastest thing humans' have ever made? Is it Voyager? It's moving at such a small fraction of the speed of light.

I guess we've made torches that make photons ...that move at the speed of light. But that feels like cheating.

21.11.2025 06:14 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
Baba Is You

I dreamt about how I would write prolog to solve this game and it's so crazy impossible. It _feels_ possible but I can't reason about it.

You should play it. hempuli.com/baba/

20.11.2025 16:31 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

BABA IS YOU AND UNREASONABLE

20.11.2025 16:31 πŸ‘ 4 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Why are so many world leaders so friggin cartoonishly evil?

And not even in a fun Pinky and the Brain way. Just slimey evil.

It might be reflecting our revealed preferences.

19.11.2025 18:35 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Are you telling me the one friggin night that I, a resident of the desert that always has clear skys, has a solar flare and the northern lights in the sky happens to happen - I also have clouds and rain?!?

Universe - you're an ass.

13.11.2025 06:02 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

You know we just don’t talk enough about the positive aspects of pollution. Like pretty sunsets. πŸ˜›

12.11.2025 01:05 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0