Does encrypting Internet traffic (possibly) create a reasonable expectation of privacy?
<p>The fourth amendment to the US constitution protects people from seizures and searches in certain situations for reasons of privacy.</p>

<p>In Katz v United States, the US Supreme Court has defined a two-part test on whether a search violates a person's right to privacy:</p>

<ul>
<li>The person must have had an expectation of privacy</li>
<li>The expectation must be reasonable</li>
</ul>

<p>When a person sends a letter, the contents of the letter are protected by the Fourth Amendment, because the letter is sealed.</p>

<p>When a person sends data on the Internet, would the same argument hold?</p>

<p>This question is asked in the light of recent attempts to force companies to create backdoors in encryption, so that they can decrypt data when requested to do so.</p>

<p>I don't think any appellate court has given an opinion on whether encryption creates a reasonable expectation of privacy. This is not surprising as only recently has it come to light that the government may have weakened encryption protocols and asked for backdoors in order to aid in decryption.</p>

<p>However, <a href="https://en.wikipedia.org/wiki/Orin_Kerr" rel="nofollow">Orin Kerr</a>, professor of Law at George Washington University School of Law wrote <a href="http://papers.ssrn.com/sol3/papers.cfm?abstract_id=927973" rel="nofollow">this article</a> in 2001. He argues that encryption <em>does not</em> create a reasonable expectation of privacy.</p>

<p>He says:</p>

<blockquote>
  <p><em>the Fourth Amendment regulates access, not understanding</em>.</p>
</blockquote>

<p>Once you introduce your communication into third party systems (or the garbage :P), they may give it up to the government. If the government happens to be able to understand that communication, so be it.</p>

<p>He shows how this conclusion is consistent with how the courts have ruled on "reassembly of shredded documents, recovery of deleted files, and the translation of foreign languages".</p>

<hr>

<p>Note that the reasonable expectation of privacy test is only one of the tests used to determine whether a search or seizure is reasonable. Another test is the "trespass" test which deems an interaction to be a search <em>per se</em> if there is a trespass on a person's personal effects. It was used before Katz and was reiterated recently in US v Jones (2012). Regardless, your question is still meaningful because the two tests are used alongside each other.</p>

united-states privacy fourth-amendment encryption