"KRACK": a severe WiFi protocol flaw

The "krackattacks" web sitediscloses a set of WiFi protocol flaws that defeat most of the protectionthat WPA2 encryption is supposed to provide. "In a keyreinstallation attack, the adversary tricks a victim into reinstalling analready-in-use key. This is achieved by manipulating and replayingcryptographic handshake messages. When the victim reinstalls the key,associated parameters such as the incremental transmit packet number(i.e. nonce) and receive packet number (i.e. replay counter) are reset totheir initial value. Essentially, to guarantee security, a key should onlybe installed and used once. Unfortunately, we found this is not guaranteedby the WPA2 protocol".