An anonymous reader quotes a report from The Guardian: Smart electricity meters, of which there are more than 100 million installed around the world, are frequently "dangerously insecure," a security expert has said. The lack of security in the smart utilities raises the prospect of a single line of malicious code cutting power to a home or even causing a catastrophic overload leading to exploding meters or house fires, according to Netanel Rubin, co-founder of the security firm Vaultra. If a hacker took control of a smart meter they would be able to know "exactly when and how much electricity you're using," Rubin told the 33rd Chaos Communications Congress in Hamburg. An attacker could also see whether a home had any expensive electronics. "He can do billing fraud, setting your bill to whatever he likes [...] The scary thing is if you think about the power they have over your electricity. He will have power over all of your smart devices connected to the electricity. This will have more severe consequences: imagine you woke up to find you'd been robbed by a burglar who didn't have to break in. "But even if you don't have smart devices, you are still at risk. An attacker who controls the meter also controls the meter's software, allowing him to cause it to literally explode." The problems at the heart of the insecurity stem from outdated protocols, half-hearted implementations and weak design principles. To communicate with the utility company, most smart meters use GSM, the 2G mobile standard. That has a fairly well-known weakness whereby an attacker with a fake mobile tower can cause devices to "hand over" to the fake version from the real tower, simply by providing a strong signal. In GSM, devices have to authenticate with towers, but not the other way round, allowing the fake mast to send its own commands to the meter. Worse still, said Rubin, all the meters from one utility used the same hardcoded credentials. "If an attacker gains access to one meter, it gains access to them all. It is the one key to rule them all."