A generation of hackers grew up tinkering with iPhones and Androids for fun, but today’s up-and-comers — thwarted by the near-ironclad security of smartphones — are shifting their focus to virtual reality headsets, self-driving cars, the cloud, mobile apps and other emerging online systems with less-tested locks. Hackers like Strafach are instrumental in rooting out vulnerabilities in software and hardware. Nowadays, the more difficult task of smartphone hacking is falling to large, more well-financed teams at cybersecurity firms and secretive government departments, all of which are prone to closely guarding those vulnerabilities for national security reasons rather than sharing them with police. “The better technology gets, the more rarefied and the smaller pool of true old-school hackers you’ll have,” said Greg Buckles, co-founder and principal analyst of forensics industry research firm EDJ Group. Strafach was one of those who specialized in jailbreaking the iPhone — finding holes in the operating system that can unleash unauthorized privileges. [...] demand for jailbreaking tools relaxed as iPhones began to include some of the functions once available only on jailbroken devices. Jailbreaking tools have been “bit-for-bit critical” for forensics software makers to provide easy ways to read the contacts, messages, app data and other information on smartphones, he said. [...] the time he and his collaborators spent looking for loose bricks increased with each new iPhone and iPhone operating system — and there were additional hurdles. Jailbreaking remains big in China, where technology giants and advertisers sponsor efforts, labor costs are lower than those in the U.S.