How can you safely store your vaccine status on your phone?

If you’re vaccinated against COVID-19 and back out in the world, chances are you’re encountering requests for your vaccination card. An increasing number of places require visitors to prove their vaccination status before being allowed in. New York City and San Francisco mandate proof of vaccination for public indoor dining, exercising, and entertainment, while New Orleans requires vaccination or a negative test. Other cities, such as Los Angeles, are considering similar measures. A