biometricReady for ID by body odor? Or the butt scan? Neither are we. But in the brave new world of the biometric revolution, biomarkers like scent and derrière shape could open doors — literally. Or start your car. Or let you vote. This is not the distant future. Around the world, governments are rolling out massive biometric identification programs. Smartphone makers are acquiring all sorts of Minority Report-ish techologies. And for scientists, the race is on to find new, workable biomarkers, which go away beyond the iris scans and fingerprints we have now. Think recognition by gait, electrocardiogram, palm vein — and, yes, eau de you and tush shape, too.  Reliable studies on the size of the biometric market are hard to come by; estimates range from $3.6 billion to nearly $7 billion. But experts agree it’s growing fast — from 7 percent to 18 percent a year, depending on who’s projecting. Markets and Marketsclaims that the biometric systems market will be worth $23.5 billion by 2020. The rapid rollout of biometric ID systems holds some promise. Hundreds of millions of people lack formal identification, and that’s an obstacle to participating in society. Without ID, it’s hard to vote, register land or get a bank account, let alone a loan. States, meanwhile, have a hard time collecting the taxes of undocumented citizens. Those are all reasons that India’s Universal ID program, which has scanned the irises of 450 million unregistered citizens, has won so many plaudits. Biometrics are a different story in the developed world. In the United States, Europe and other regions, the worry is not that the state doesn’t know who you are, but that it knows too well — like Big Brother. Critics of biometric programs argue that important questions haven’t been resolved.

Who has the right to collect your biodata? Who gets to access it? How can it be used? And what happens in case of security failures? After all, you can change your passwords after a Heartbleed bug, but you can’t change your irises. Even agnostics agree that laws haven’t kept pace with the technology. “The technology itself is ethically neutral,” says Alan Gelb, a researcher at the Center for Global Development who studies national ID systems, including biometrics. “The question is how the technology is used.” But Gelb says there’s not enough oversight or regulation of the technologies. Although the 160 national ID programs Gelb and his co-researcher found go a long way toward bridging the “identity gap,” half of them lack adequate data-protection laws, he said. That’s one reason Scientific American argued in December that the biometric revolution “makes possible privacy violations that would make the National Security Agency’s data sweeps seem superficial by comparison.” Much biometric data are collected without the subject’s explicit consent — or even knowledge, says Jennifer Lynch, a senior attorney at the Electronic Frontier Foundation (EFF). Little is known about how it is used. Security is at stake, too, because biometric data is hard (if not impossible) to revoke or replace. “Data breaches occur all the time — who might get control of that data?” says Lynch. “I think we should be incredibly concerned over this.” More