You’ve been lawfully arrested. The police have lawfully seized your computers. You’ve encrypted some or all of your data. Can the police legally compel you to provide the encryption key? The answer in the United States is “yes”. Although, the Fifth Amendment provides that “no person … shall be compelled in any criminal case to be a witness against himself”, an accused could be compelled to provide police with the encryption key to all his or her computers if factual statements conveyed were foregone conclusions and therefore the act of decryption was not testimonial communication protected by the Fifth Amendment. Sections 11(c) and 13 of the Charter of Rights and Freedoms cover non-compellability and privilege against self-incrimination; however Canadian courts have yet to grapple with the issue of mandatory key disclosure on a constitutional level. When can a person be required to provide authorities with an encryption key? By what mechanism?