  The Advanced Metering Infrastructure (AMI) is a vital element in the current
development of the smart grid. AMI technologies provide electric utilities with
an effective way of continuous monitoring and remote control of smart grid
components. However, owing to its increasing scale and cyber-physical nature,
the AMI has been faced with security threats in both cyber and physical
domains. This paper provides a comprehensive review of the crucial
cyber-physical attacks and counter defense mechanisms in the AMI. First, two
attack surfaces are surveyed in the AMI including the communication network and
smart meters. The potential cyber-physical attacks are then reviewed for each
attack surface. Next, the attack models and their cyber and physical impacts on
the smart grid are studied for comparison. Counter defense mechanisms that help
mitigate these security threats are discussed. Finally, several mathematical
tools which may help in analysis and implementation of security solutions are
summarized.
