Denial of service type attacks are attacks where the nature of a system
used to establish communication sessions is exploited to prevent the
establishment of sessions. For example, to establish a Transmission
Control Protocol (TCP)/Internet Protocol (IP) communication session, a
three-way handshake is performed between communication endpoints. When a
connection request is received, resources are allocated towards
establishing the communication session. Malicious entities can attack the
handshake by repeatedly only partially completing the handshake, causing
the receiving endpoint to run out of resources for allocating towards
establishing sessions, thus preventing legitimate connections.
Illustrated embodiments overcome such attacks by delaying allocating
resources until after the three-way handshake is successfully completed.