jpol

Imprisonment for civil contempt can be of unlimited duration, but the purpose of it is to force you to give up the information. Once you have been in jail long enough for the judge to realize that imprisoning you won't change your mind, you will be released. That could be a very long time.

U.S. v. Hubbell, citing U.S. v. Doe.

For these reasons, we cannot accept the Government's submission that respondent's immunity did not preclude its derivative use of the produced documents because its "possession of the documents [was] the fruit only of a simple physical act-the act of producing the documents." Id., at 29. It was unquestionably necessary for respondent to make extensive use of "the contents of his own mind" in identifying the hundreds of documents responsive to the requests in the subpoena. See Curcio v. United States, 354 U. S. 118, 128 (1957); Doe v. United States, 487 U. S., at 210. The assembly of those documents was like telling an inquisitor the COMBINATION TO A WALL SAFE, not like being forced to surrender the key to a strongbox. Id., at 210, n. 9.

http://supreme.justia.com/cases/federal/us/530/27/case.html

Criminal contempt would have to be proven beyond a reasonable doubt, and the elements of proving the defendant's failure to provide the encryption key would include (1) showing that the key exists and (2) showing that they key is in the defendant's possession.

Shorter Version:

It does not matter whether the government forces you to do something (e.g. open a combination lock), as opposed to providing information (e.g. tell them the combination). The deciding factor is whether there is an invasion of your mental privacy inherent in the government compulsion. Whether you disclose the combination or open the lock yourself, the contents of your mind are being used to incriminate you, so your Fifth Amendment rights are being violated. This is distinct from the government demanding the key to a safe, or even taking a blood sample from you against your will, both of which are purely physical impositions.

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Longer Version:

If the police have a warrant to search your documents, that does not mean that they can make you provide the documents to them. They can look through your stuff to find the documents, but if the police cannot read them, that is their problem.

However, a grand jury can subpoena documents from you, in which case you will be compelled to provide them. In this case, you can invoke the Fifth Amendment privilege against testimonial self incrimination as it relates to the production of documents. To the extent that the act of producing the documents requires you to use the contents of your mind, the act of production cannot be used to incriminate you. So, on one hand, your Fifth Amendment right will not protect you if the police already know that the documents exist and all of the information that is contained in them. However, if the police do not know exactly what documents they are looking for and what the documents say, then the information found in the documents cannot be used against you in court, nor can it be used to find other incriminating information.

See U.S. v. Hubbell, 530 U.S. 27 (Supreme Court case from 2000) http://supreme.justia.com/cases/federal/us/530/27/case.html