All-Optical Networks provide ultra-fast data rates, but present a new set of challenges for network security. However optical performance monitoring (OPM) and optical network management (ONM) are essential in building a reliable, high-capacity, and service-differentiation enabled all-optical network. One of the serious problems with transparency is the fact that optical crosstalk is additive, and thus the aggregate effect of crosstalk over a whole AON may be more nefarious than a single point of crosstalk. Attacks can spread rapidly through the network, causing additional awkward failures and triggering multiple undesirable alarms, they must be detected and identified at any point in the network where they may occur. This results in the continuous monitoring and identification of the impairments becoming challenging in the event of transmission failures. However, a simple and reliable signal quality monitoring method does not exist at present. In this paper we present a novel method for attack identification and localization in networks with a minimum of complexity and cost. This method can participate in some tasks for fault management in optical network.