From mboxrd@z Thu Jan 1 00:00:00 1970 Path: eternal-september.org!news.eternal-september.org!feeder3.eternal-september.org!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Niklas Holsti Newsgroups: fr.comp.lang.ada,comp.lang.ada Subject: Re: Canal+ crash Date: Sun, 21 Jul 2024 14:31:27 +0300 Organization: Tidorum Ltd Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: individual.net P/efkD/mCEg6P72+84ExTACIJaHmrRGT7MHpvBzG9rgcjZYupk Cancel-Lock: sha1:5LuFM9BuTEU1vcSF4y9OVe5BOcQ= sha256:EagtEp8dOqSjUSnbL8F8X2dWjmCpx2oyLirTuhKhQVA= User-Agent: Mozilla Thunderbird Content-Language: en-US In-Reply-To: Xref: news.eternal-september.org fr.comp.lang.ada:2294 comp.lang.ada:66238 List-Id: On 2024-07-21 12:19, Dmitry A. Kazakov wrote: > On 2024-07-21 10:00, Niklas Holsti wrote: >> On 2024-07-21 10:22, Dmitry A. Kazakov wrote: >>> On 2024-07-21 03:04, Lawrence D'Oliveiro wrote: >>>> On Sat, 20 Jul 2024 11:08:47 +0200, Dmitry A. Kazakov wrote: >>>> >>>>> On 2024-07-20 09:43, Lawrence D'Oliveiro wrote: >>>>> >>>>>> On Sat, 20 Jul 2024 09:23:11 +0200, Dmitry A. Kazakov wrote: >>>>>> >>>>>>> It is about the fundamental principle that security cannot be >>>>>>> added on >>>>>>> top of an insecure system. >>>>>> >>>>>> Actually, it can. Notice how the Internet itself is horribly >>>>>> insecure, >>>>>> yet we are capable of running secure applications and protocols on >>>>>> top >>>>>> of it. >>>>> >>>>> Why on earth do we need security updates? >>>> >>>> Because computer systems are complex, and new bugs keep being >>>> discovered >>>> all the time. >>> >>> This does not make sense. You can create a very complex system out of >>> screwdrivers and still each screwdriver would require no update. >>> >>> Systems consist of computers and computers of software modules. There >>> is nothing inherently complex about making a module safe and bug >>> free. Security interactions are primitive and 100% functional. There >>> is no difficult issues with non-functional stuff like real-time >>> problems. >> >> Well, several recent attacks use variations in execution timing as a >> side-channel to exfiltrate secrets such as crypto keys. The crypto >> code can be functionally perfect and bug-free, but it may still be >> open to attack by such methods. > > It is always a tradeoff between the value of the information and costs > of breaking the protection. I doubt that timing attack are much more > feasible in that respect than brute force. Security researchers and crypto implementers seem to take timing attacks quite seriously, putting a lot of effort into making the crucial crypto steps run in constant time. >> But certainly, most attacks on SW have used functional bugs such as >> buffer overflows. > > Exactly. Non-functional attacks are hypothetical at best. They rely on > internal knowledge which is another problem. As I understand it, the "internal knowledge" needed for timing attacks is mostly what is easily discoverable from the open source-code of the SW that is attacked.