If I had looked closer I would have respected that American history has shown a deep respect for keeping communications secret. Everyone from Jefferson and Madison to Abigail Adams tried to keep their communications secret. The Founders used secret communications methods to deny information to those not intended to receive it and to act as a "secure seal." Ralph E. Weber, United States Diplomatic Codes and Ciphers, 1775-1938 88 (1979). "As rebels and conspirators, the young nation's leaders ... turned to codes and ciphers in an effort to preserve the confidentiality of their communications. One of the earliest acts of the Continental Congress was to order that its Committee handling foreign correspondence use "cyphers." Ralph E. Weber, Masked Dispatches: Cryptograms and Cryptology in American History, 1775-1900 5-6 n.6. (1993). “During the Revolutionary period cipher was employed extensively not only in public correspondence where secrecy was especially important but in the private correspondence of public men as well." Edmund Cody Burnett, Ciphers of the Revolutionary Period, 22 American Historical Review 329 (1917). "In the years after 1780, Jefferson, James Madison, James Monroe, and a covey of other political leaders in the United States often wrote in code in order to protect their personal views on tense domestic issues confronting the American nation. Employing many codes and a few ciphers, they sought safety for their dispatches: they built security fences to protect their correspondence from political rivals and American postal officials.” ,Masked Dispatches: Cryptograms and Cryptology in American History, at 6.
Hit the fast forward button to move us to the present and people continue to do today what was done yesterday: communicate in secret. As always, the government says it has legitimate reasons to snoop into a citizen’s personal business. For instance, in In re Grand Jury Subpoena Duces Tecum (Doe), 670 F.3d 1335 (11th Cir. 2012). A grand jury issued a subpoena commanding Doe to decrypt and produce data from the laptop computers and hard drives, and Doe informed the US attorney that he refused to comply because doing so would violate his Fifth Amendment privilege against self-incrimination. Recall that the Fifth Amendment protects the accused against perjury, contempt, or providing evidence against themselves. Akhil R. Amar & Renee B. Lettow, Fifth Amendment First Principles: The Self-Incrimination clause, 93 MICH. L. REV. 857, 890 (1995). Moreover, protects for the dignity of an individual's private thoughts from government invasion. Michael Dann, The Fifth Amendment Privilege Against Self-Incrimination: Extorting Physical Evidence from a Suspect, 43 S. CAL. L. REV. 597, 611 (1970). The prosecutor tried to end run the Fifth Amendment protections by getting a trial court order that granted Doe immunity for production of the data. However, the immunity was limited to the act of producing the data; in other words, the government could make “derivative use” of the data in a criminal prosecution of Doe.
The Eleventh Circuit held that the act of decryption and production would constitute testimony, which would implicate the Fifth Amendment. The Eleventh Circuit also held that the trial judge “erred in limiting [Doe’s] immunity . . . to the Government’s use of his act of decryption and production, but allowing the Government derivative use of the evidence such act disclosed.” Doe, 670 F.3d at 1341. In reaching this decision, the Doe court explained that “even if the decryption and production of the contents of the hard drives themselves are not incriminatory, they are a “link in the chain of evidence” that is designed to lead to incriminating evidence; this is sufficient to invoke the Fifth Amendment privilege. Hoffman v. United States, 341 U.S. 479, 486, 71 S. Ct. 814, 818, 95 L. Ed. 1118 (1951) (“The privilege afforded [by the Fifth Amendment] not only extends to answers that would in themselves support a conviction under a federal criminal statute but likewise embraces those which would furnish a link in the chain of evidence needed to prosecute.” In re Grand Jury Subpoena Duces Tecum (Doe), at note 15. Citing Curcio v. United States, 354 U.S. 118, 128, 77 S. Ct. 1145, 1151 (1957), the Doe court explained that an act of production is testimonial when “the government compels the individual to use ‘the contents of his own mind’ to explicitly or implicitly communicate some statement of fact.” Under this test, “the decryption and production would be tantamount to testimony by Doe of his knowledge of the existence and location of potentially incriminating files; of his possession, control, and access to the encrypted portions of the drives; and of his capability to decrypt the files.” Doe, at 1346.
Finally, the Eleventh Circuit stated that the district court could have compelled decryption if it had offered "constitutionally sufficient immunity" and the government had shown that the accused was actually capable of decrypting the drive. Id. at 1349–50. Referring to the landmark case of Kastigar v. United States, 406 U.S. 441 (1972) the Eleventh Circuit noted that to be constitutionally sufficient, the immunity must be "co-extensive with the scope of the privilege." Id. at 1350–51. Although not mentioned by the Eleventh Circuit here, the finding that a password was testimonial has also been reached by district courts. See e.g. U. S. v. Kirschner, 823 F. Supp. 2d 665 (E.D. Mich. 2010). In Kirschner, the accused was subpoenaed to testify and provide his passwords to a grand jury. Id. at 666. The court found that the passwords were testimonial and therefore protected by the Fifth Amendment. Id. at 669.