{"guid":"064a7014-a88c-462a-b06f-7d6de62d622f","title":"Provable Security","subtitle":"How I learned to stop worrying and love the backdoor","slug":"35c3-9517-provable_security","link":"https://fahrplan.events.ccc.de/congress/2018/Fahrplan/events/9517.html","description":"Modern cryptography is based on security-proofs. We will demonstrate how these work, why they are desirable and what their limitations are.\n\n\u003cp\u003eEven the use of secure primitives like AES or RSA does not guarantee that the end-result is secure as well. In recent years breaks of modern primitives have in fact become exceedingly rare, yet stories like the KRACK-attack or ROBOT keep appearing.\u003c/p\u003e\n\n\u003cp\u003eThe obvious answer to these problems would be to proof that our protocols are secure. While that may sound great in theory, there are many issues as well:\u003c/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eProving (almost) anything secure, would require to solve a millennium-problem.\u003c/li\u003e\n\u003cli\u003eGiven the above, assumptions are required; but which assumptions are reasonable?\u003c/li\u003e\n\u003cli\u003eThe word “secure” may seem intuitive, but can we formally define it? And can something be \u003cem\u003etoo\u003c/em\u003e secure?\u003c/li\u003e\n\u003cli\u003eIdealizing primitives can solve many problems, but what about over-idealizations?\u003c/li\u003e\n\u003cli\u003eCan backdoors be necessary to prove security?\u003c/li\u003e\n\u003cli\u003eA proof can only show the absence of attacks in a certain model. What about attacks outside those models?\u003c/li\u003e\n\u003c/ul\u003e\n\n","original_language":"eng","persons":["FJW","Lukas"],"tags":["35c3","9517","Security"],"view_count":1712,"promoted":false,"date":"2018-12-29T00:00:00.000+01:00","release_date":"2018-12-29T01:00:00.000+01:00","updated_at":"2026-04-01T10:30:04.554+02:00","length":3545,"duration":3545,"thumb_url":"https://static.media.ccc.de/media/congress/2018/9517-hd.jpg","poster_url":"https://static.media.ccc.de/media/congress/2018/9517-hd_preview.jpg","timeline_url":"https://static.media.ccc.de/media/congress/2018/9517-hd.timeline.jpg","thumbnails_url":"https://static.media.ccc.de/media/congress/2018/9517-hd.thumbnails.vtt","frontend_link":"https://media.ccc.de/v/35c3-9517-provable_security","url":"https://api.media.ccc.de/public/events/064a7014-a88c-462a-b06f-7d6de62d622f","conference_title":"35C3: Refreshing 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