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> I use the most aggressive attackers as my threat model. Is that what you chose out of interest, or do you actually need it? I will assume the former, because

by palata 2y ago

> I use the most aggressive attackers as my threat model. Is that what you chose out of interest, or do you actually need it? I will assume the former, because that's how your question sounds. My answer in that case would be: you need to work on your threat model. It is tempting to say "I want the best security, therefore I will define my threat model as 'the most aggressive one'". But that is a fallacy: the best security model is the one that fits your use-case best, not the one that defends against most attackers. Security is always a tradeoff. Remember that you need security fundamentally because what you want to do has some inherent risk (small or high). The whole point is to decide what risk you can afford and find a security model that is acceptable under those conditions. If you say "I can't take any risk at all", then the answer is always "don't do anything at all". But if you say "I am making a connected fridge for my home and I really want to make sure that the NSA won't be able to shut it down remotely", then the answer is most likely that your threat model is wrong. Because you actually don't really care about the NSA shutting down your fridge: you can probably live with that risk. To go back more concretely on your specific question ("which OS should I use against the most aggressive attacker?"), it means that you are probably simply not competent to defend against the most aggressive attacker. There is no such thing as "the most secure OS" if you don't know how to configure and use it properly, and there is arguably no such thing as "security against the most aggressive attacker". If that's out of interest, I would suggest you pick a realistic threat model and try to reason about it. If you have an actual need (e.g. you need to contact a journalist or something), then try to be more specific than "the most aggressive attacker".

nicecars 2y ago
Sorry for the uninformed question. I asked this question out of interest. The most aggressive attacker is because I recall that there used to be a criterion on Wikipedia (I don't remember which page, but I heard it was cancelled when the criterion could no longer be met) where the NSA or another US government agency had a kernel of resistance for the most aggressive attacker.
- palata 2y ago
  > Sorry for the uninformed question Don't be! It's good to think about security :-). But keep in mind that "the most aggressive attacker" is a bit of a poor threat model. It sounds like a shortcut for not having to think about it, and therefore it misses the point. For instance: - Could it be the case that someone points a gun to your head and asks you to give access to your OS? Probably not => that's a first step in defining your threat model, where you can assume that nobody will force you to give up your password. - Will someone have physical access to your computer? If you have a laptop that you carry around, it may get lost/stolen and therefore you probably want encryption at rest (i.e. full disk encryption). Even if it is your desktop computer at home, one could imagine that it gets stolen. If it is a desktop computer at work, then employees may have access to it. If not encrypted, they could just read what's on the disk. Or they could plug a keylogger and read everything that you type on your keyboard, etc. - Will your OS be exposed to the Internet? Will it expose ports or can it be completely hidden behind a firewall? - Are you the only user, or is it possible that another user gets phished? - etc. Those are all questions (but it is not an exhaustive list) you need to ask to decide what is an acceptable security model. If all you do is browse the web, maybe you don't need QubesOS (because you don't have anything to compartmentalize). If you sometimes need to write an email anonymously, again maybe you don't need QubesOS but you could go with TailsOS. Depending on the threat model, maybe you will want a brand new computer just for the "sensitive" activity you have, and maybe you will only connect to the Internet from "outside" (i.e. not your personal WiFi). Etc.
  - nicecars 2y ago
    Thank you! Now I understand that my threat model is not good! I remembered the NSA criteria, Separation Kernel Protection Profile

by palata 2y ago

nicecars 2y ago

Sorry for the uninformed question. I asked this question out of interest. The most aggressive attacker is because I recall that there used to be a criterion on Wikipedia (I don't remember which page, but I heard it was cancelled when the criterion could no longer be met) where the NSA or another US government agency had a kernel of resistance for the most aggressive attacker.

palata 2y ago
> Sorry for the uninformed question Don't be! It's good to think about security :-). But keep in mind that "the most aggressive attacker" is a bit of a poor threat model. It sounds like a shortcut for not having to think about it, and therefore it misses the point. For instance: - Could it be the case that someone points a gun to your head and asks you to give access to your OS? Probably not => that's a first step in defining your threat model, where you can assume that nobody will force you to give up your password. - Will someone have physical access to your computer? If you have a laptop that you carry around, it may get lost/stolen and therefore you probably want encryption at rest (i.e. full disk encryption). Even if it is your desktop computer at home, one could imagine that it gets stolen. If it is a desktop computer at work, then employees may have access to it. If not encrypted, they could just read what's on the disk. Or they could plug a keylogger and read everything that you type on your keyboard, etc. - Will your OS be exposed to the Internet? Will it expose ports or can it be completely hidden behind a firewall? - Are you the only user, or is it possible that another user gets phished? - etc. Those are all questions (but it is not an exhaustive list) you need to ask to decide what is an acceptable security model. If all you do is browse the web, maybe you don't need QubesOS (because you don't have anything to compartmentalize). If you sometimes need to write an email anonymously, again maybe you don't need QubesOS but you could go with TailsOS. Depending on the threat model, maybe you will want a brand new computer just for the "sensitive" activity you have, and maybe you will only connect to the Internet from "outside" (i.e. not your personal WiFi). Etc.
- nicecars 2y ago
  Thank you! Now I understand that my threat model is not good! I remembered the NSA criteria, Separation Kernel Protection Profile