Ce que pense Bruce Schneier à propos des apps de traçage des contacts #Covid

Le spécialiste de sécurité reconnu qu’est Bruce Schneier à un avis bien arrêté sur les apps de traçage des contacts : Inutiles et sans valeur. Il est évident qu’une application seule ne pourra pas freiner la propagation de ce virus sans une large adoption et sans une coordination intelligente avec les services de santé ( pour les tests en particulier).

This is a classic identification problem, and efficacy depends on two things: false positives and false negatives.False positives: Any app will have a precise definition of a contact: let’s say it’s less than six feet for more than ten minutes.

– The false positive rate is the percentage of contacts that don’t result in transmissions. This will be because of several reasons. One, the app’s location and proximity systems — based on GPS and Bluetooth — just aren’t accurate enough to capture every contact. Two, the app won’t be aware of any extenuating circumstances, like walls or partitions. And three, not every contact results in transmission; the disease has some transmission rate that’s less than 100% (and I don’t know what that is).

– False negatives: This is the rate the app fails to register a contact when an infection occurs. This also will be because of several reasons. One, errors in the app’s location and proximity systems. Two, transmissions that occur from people who don’t have the app (even Singapore didn’t get above a 20% adoption rate for the app). And three, not every transmission is a result of that precisely defined contact — the virus sometimes travels further.

Bruce Schneier