During the course of World War Two in the Pacific there were numerous primitive cultures on remote islands that came into contact with Westerners for the first time. Islanders were particularly impressed with the cargo that the visitors brought with them. At the conclusion of World War Two most of the visitors left and the cargo stopped arriving. Across multiple islands separated by thousands of miles a strange phenomenon occurred. Primitive cultures attempted to invite new cargo by imitating the conditions of what was happening when the cargo was arriving. They cleared spaces for aircraft landing strips and “controllers” dressed up with vines for wires and sticks for microphones. Bizarre ritualised behaviour developed around the use of artefacts like uniforms and insignias. “Cargo Cult” behaviour was a phrase coined by the scientist Richard Feynman to explain activity that occurs where appearances are superficially imitated. A result is pursued without actually understanding the underlying mechanisms of cause and effect. Pre-requisites are mistaken for causation. The pattern across so many independent island cultures suggests that this confusion is part of human nature. A good causation parody you may have heard of is a lack of pirates causes global warming.
What if much of our security advice to users was a waste of their time? What if some of it actually made users worse off? These are bold words but stay with me and let’s see where this goes. There will be some maths on the journey but it will be worth it I promise. Let’s look at passwords as an example. Many thousands of pages of security policy have been generated on creating strong passwords. It’s one of the most common subjects for security awareness. More letters, more numbers, make it longer and put a special character in it. Actually, most passwords don’t need to be strong, they just need to be difficult to guess which isn’t the same thing. Cormac Herley points out that password strength no longer has the critical role in security that it used to. It’s largely irrelevant since most systems now control the rate of password guessing attempts. For example only allowing five attempts every 30 minutes. In this scenario, the difference between 7 character and 8 character passwords is negligible if the system limits a brute force attack to 240 attempts per day. Modern authentication systems are much more likely to be compromised by password database disclosures, password re-use and key-loggers. Complexity does not assist with managing any of these threats. For years we’ve been focused on complexity and as a result users come up with combinations like “Password1” which meet our complexity rules but don’t effectively mitigate their risks. We need to change. We need to stop talking about password complexity and start talking about password commonality. Potentially, we’re doing more harm than good by occupying valuable (and limited) attention spans with topics of marginal return. The risks have changed and our risk communication needs to reflect that.