When it's time for a selfie, many Chinese people would make a V-sign for the camera. V-for-victory is their way of saying cheese.
But this popular ritual could expose you to fingerprint theft, said a Chinese cybersecurity expert.
Zhang Wei, the vice-director of the Shanghai Information Security Trade Association, said if held close enough to the camera, the picture could reveal a perfect fingerprint.
Photo magnifying and artificial intelligence-enhanced technologies make it possible to extract enough detail to make a perfect copy, he added.
Zhang said if a V-sign is photographed within 5 feet, fingerprints can be clearly extracted and copied.
When extracted from photos, fingerprints could be turned into molds, unlocking a wide range of physical and digital entry points, he said.
To avoid any potential issues, he suggests getting 10 feet away from the camera if making a V-sign.
Zhang's warning has led to widespread concern on China's social media. His remarks have gathered more than 450 million views on China's Twitter-like Weibo by Thursday night.
"Advanced technology has brought us convenience but meanwhile has also brought us risk and danger. What can we do now?" one popular commenter said.
Feng Jianjiang, a professor of fingerprint identification at Tsinghua University, told the South China Morning Post that, theoretically, pictures could show fingerprints clear enough to be copied, but he didn't comment on Zhang's suggested distances.
"Some people's fingerprints could not be captured (at any distance) because of skin problems (for example)," Feng said. "But the fingerprint images would be fairly clear if the distance, angle, focus and lighting were all ideal."
Feng suggested people check the clarity of detail by zooming in on their fingerprints in pictures before uploading them to social media.
Some Chinese netizen said highly altered photos from beautifying filters will make it harder to expose identity information.
"Chillax, guys, aren't we all using beauty cams these days? I doubt they can find fingerprints after all these re-touches and compression." one Weibo commentator said.
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