Security aspects for IEEE 1588 based clock synchronization protocols

The synchronization of clocks in distributed systems is an enabling technology for many applications. Often clock synchronization is done in a master-slave fashion in order to gain high and predictable accuracy. Well-known representatives of this approach are IEEE 1588 and simplified forms of single-master NTP (Network Time Protocol). Although the simplicity of the master-slave (1:n) approach has advantages for implementation and operation compared to democratic approaches, it is also very vulnerable to failures or malicious attacks. One example is the poor ability to react on the fact that any malicious master, e. g., a Byzantine or “babbling idiot” node, has the potential to compromise all connected nodes with a wrong clock value. Available protocols solve the problem of correct synchronization of clocks in distributed systems, but poorly handle security. This paper will investigate common security properties of master-slave based clock synchronization algorithms, analyse the applicable threats and propose countermeasures to achieve more dependable systems.