I have come across accounts of more forceful examination of electronic devices at United States border points. I possess considerable knowledge about safeguarding computers, yet I am rather uninformed regarding the protection of smartphones.

Are there simple methods to erase data—documents, images, etc.—on smartphones so it cannot be retrieved? Does restoring a phone to its original settings eliminate data, or is it still retrievable? In other words, does the restoration remove the previous encryption key, or merely disconnect the password that grants access to that key? Upon rebooting the phone, are the deleted files still accessible?

We require solutions for both iPhones and Android devices. Furthermore, this issue extends beyond the US; the global landscape is likely to become increasingly perilous for those who challenge governmental authority.