February 8, 2023

Archives for October 2014

Bitcoin mining is NP-hard

This post is (mostly) a theoretical curiosity, but a discussion last week at CITP during our new course on Bitcoin led us to realize that being an optimal Bitcoin miner is in fact NP-hard. NP-hardness is a complexity classification used in computer science to describe many optimization problems for which we believe there is no algorithm […]

Four Fair Use Takeaways from Cambridge University Press v. Patton

The most important copyright and educational fair use case in recent memory (mine, at least) was decided by the Eleventh Circuit Court of Appeals last week. The case, Cambridge University Press v. Patton, challenged Georgia State University’s use of e-reserves in courses offered by the university. The copyrighted works at issue were scholarly books–i.e., a […]

POODLE and the fundamental market failure of browser security

Last week saw the public disclosure of the POODLE vulnerability, a practical attack allowing a network attacker to steal plaintext from HTTPS connections. In particular, this attack can be used to steal authentication cookies. It’s a bad vulnerability, and it particularly hurts because it should have been fixed long ago. It only affects the ancient SSL v3 protocol, which was […]

On the value of encrypting your phone

This is a true story. Yesterday my phone crashed, and it wouldn’t reboot. Actually it would do nothing but reboot, over and over, with a seemingly different error message every time. I tried all of the tricks available to a technically handy person, and nothing worked—I couldn’t get it out of the crash-reboot cycle. So […]

Guessing passwords with Apple’s full-device encryption

With the recently-introduced iOS 8, Apple has switched to a encrypting a much larger amount of user data by default. Matt Green has provided an excellent initial look at a technical level and big-picture level and Apple has recently released a slightly more detailed specification document and an admirable promise never to include backdoors. This move, and Google’s prompt promise […]