Best of 2025

The blog posts Hacker News loved most in 2025. 371 posts.

Security & Privacy
345

Cell Phone OPSEC for Border Crossings

I have heard stories of more aggressive interrogation of electronic devices at US border crossings. I know a lot about securing computers, but very little about securing phones. Are there easy ways to delete data—files, photos, etc.—on phones so it can’t be recovered? Does resetting a phone to factory defaults erase…

349

Towards a test suite for TOTP codes

Because I'm a massive nerd, I actually try to read specification documents. As I've ranted ad nauseam before, the current TOTP spec is irresponsibly obsolete. The three major implementations of the spec - Google, Apple, and Yubico - all subtly disagree on how it should be implemented. Every other MFA app has their own…

360

Entropy Attacks

The conventional wisdom is that hashing more entropy sources can't hurt: if H is any modern cryptographic hash function then H(x,y,z) is at least as good a random number as H(x,y), no matter how awful z is. So we pile one source on top of another, hashing them all together and hoping that at least one of them is good.