Would this be a 5th Amendment issue in the U.S. ??

Two Brits are going to prison because they have refused to give authorities the decryption keys to unlock information stored on their computers.

The power to force people to unscramble their data was granted to authorities in October 2007...

The former High Court judge did not provide details of the crimes being investigated in the case of either individual - neither of whom were necessarily suspects - nor of the sentences they received.

In the U.S. this power might (or might not) be challenged under the provisions of the 5th Amendment to the Constitution: "...nor shall [any person] be compelled in any criminal case to be a witness against himself..."

Personally, I suspect in the U.S. the provisions of the Patriot Act would be used to override any protections of the Constitution.

Long discussion thread at Reddit on this subject.