Vacon Plc, Nixu Ltd and F-Secure Corporation have collaborated on a white paper on industrial automation security. The white paper has been published on Vacon's website. There has been a lot of discussion about malware and security in industrial automation systems after Stuxnet. This white paper focuses on presenting a generic overview about security in industrial automation on the fieldbus and device level. The standardization bodies in the information security field are presented, and activities in industrial automation security standardization are discussed. Security aspects of traditional fieldbuses, Ethernet-based industrial networks and wireless communication technologies are presented. Challenges regarding data security in the field of industrial automation are also discussed. The properties of industrial automation devices are described with a focus on security, tampering possibilities, and risk mitigation methods. The white paper also includes practical recommendations for improving information security in industrial processes.