• 0 Posts
  • 30 Comments
Joined 1 year ago
cake
Cake day: June 21st, 2023

help-circle
  • Wikpedia puts it nicely:

    "The concept of concurrent computing is frequently confused with the related but distinct concept of parallel computing,[3][4] although both can be described as “multiple processes executing during the same period of time”. In parallel computing, execution occurs at the same physical instant: for example, on separate processors of a multi-processor machine, with the goal of speeding up computations—parallel computing is impossible on a (one-core) single processor, as only one computation can occur at any instant (during any single clock cycle).[a] By contrast, concurrent computing consists of process lifetimes overlapping, but execution does not happen at the same instant. "


  • A cpu (core) can only do one thing at a time. When you have multiple cores you can do multiple things at the same time. Multitasking in programming sense is a bad term, it’s a term more for the masses.

    Bit simplified:

    • concurrency: you seem to be doing multiple things at the same time. In reality they are run little by little one after another. Doesn’t really speed things up.
    • parallelism: you actually run multiple things at the same time (multiple cpus/cpu cores required). If the code scales properly or is designed to truly run in parallel the speed up is relative to the number of cpus available.

    Edit: It’s much more complex subject then I’ve presented here.









  • Whatsapp uses the same protocol as signal so MITM is unlikely however there’s no way to know what happens before or after the messages are encrypted/decrypted and sent. They can do that scanning at that stage.

    That is different than Signal which (unless they changed something with the profiles thing) was always P2P E2EE. You’re sending encrypted messages directly to the other persons phone, not to a server.

    Sender cannot know where the recipient is and using P2P would be resource consuming on all client devices (i.e. everyone who uses Signal) so I guess the messages are routed thru Signal’s servers though messages are encrypted on device with keys that only the messaging parties know (couldn’t find an official diagram for this to confirm).