Wanted: App with hot key that can wipe a phone's contents
bbc.co.uk
bbc.co.uk
Also wanted: custom bootloaders for androids that will self-wipe if the phone is powered on without a certain button combo.
In the second scenario, you're a hardened terrorist who has just been caught red-handed selling child pornography in order to fund an international drug deal with the Iranian Revolutionary Guard. In this case, the police will go to great lengths to extract data from your phone, and will force you to hand over encryption keys. Here you probably want your phone to self-destruct as completely as possible, at the very least wiping all data from it.
My point is that the self-destruct option is only a good fit for someone who expects to face a serious attempt at data extraction. Encryption should be sufficient to prevent casual snooping from any attackers, police included.
> the advantage of encryption is that your phone remains usable once you decrypt the data again.
Assuming the police don't damage the phone or data in attempts to extract data. And assuming they keep it for a reasonable length of time, and not for months while they slowly grind through the process of finding forensic examiners who'll look at it.
You mention laws that force users to hand over encryption keys. These are worrying! In the UK that'd be RIPA.
(http://en.wikipedia.org/wiki/Regulation_of_Investigatory_Pow...)
Here's a quote from the wiki article:
> The first person jailed under RIPA Part III, for not giving police access to encrypted material, was a schizophrenic man who was later judged to be no threat to national security. He said he was refusing to provide keys on principle, on the basis that he should have a right to silence. He was jailed for 9 months for refusing to hand over his decryption keys, or otherwise decrypt the data, and was later moved to a secure mental hospital part way through his sentence. Notably, the encrypted material in question was not suspected of securing illegal material.
EDIT: The article says that the phone data is only taken when the phones are suspected of being used in crime, and that the data is kept, so the police will want to decrypt it.