“KRACK”: a severe WiFi protocol flaw

Post Syndicated from corbet original https://lwn.net/Articles/736486/rss

The “krackattacks” web site
discloses a set of WiFi protocol flaws that defeat most of the protection
that WPA2 encryption is supposed to provide. “In a key
reinstallation attack, the adversary tricks a victim into reinstalling an
already-in-use key. This is achieved by manipulating and replaying
cryptographic 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 to
their initial value. Essentially, to guarantee security, a key should only
be installed and used once. Unfortunately, we found this is not guaranteed
by the WPA2 protocol