The Privacy BlogThoughts on privacy, security, and other stuff.

TAG | law enforcement

ArsTechnica has a nice article on a recent ruling by the US Fifth Circuit court of appeals.

In this 2-1 decision, the court ruled that cellular location information is not covered by the fourth amendment, and does not require a warrant. The logic behind this ruling is that the information is part of business records created and stored by the mobile phone carriers in the ordinary course of their business.

Therefor, the data actually belongs to the phone company, and not to you. The Stored Communications Act says that law enforcement must get a warrant to obtain the contents of communications (the body of emails or the audio of a phone call) but not for meta-data like sender, recipient, or location.

The court suggests that if the public wants privacy of location information that they should demand (I suppose through market forces) that providers delete or anonymize the location information, and that legislation be enacted to require warrants for access to it. Until then, they say we have no expectation of privacy in that information.

The Fifth Circuit covers Louisiana, Mississippi, and Texas.

This ruling conflicts with a recent New Jersey Supreme Court, which unanimously ruled that law enforcement does not have that right, which ruling only applies in New Jersey.

Montana has a law requiring a warrant to obtain location information, while in California a similar bill was vetoed.

It seems very likely that one or more of these cases will go to the supreme court.

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Jun/13

4

Can you be forced to decrypt your files?

Declan McCullagh at CNET writes about the most recent skirmish over whether a person can be forced to decrypt their encrypted files.

In this case, Jeffery Feldman is suspected of having almost 20 terabytes of encrypted child pornography. Evidence of use of eMule, a peer to peer file sharing tool, showed filenames suggestive of such content. Child porn makes for some of the worst case law because it is such an emotionally charged issue.

A judge had ordered Mr. Feldman to decrypt the hard drive, or furnish the pass phrase, by today. After an emergency motion, he has been given more time while the challenge to the order is processed.

The challenge is over whether being compelled to decrypt data is equivalent to forced testimony against one’s self, which is forbidden by the Fifth Amendment. The prosecution position is that an encryption key is similar to a key to a safe, which may be compelled. Some prior cases have come down on the side of forcing the decryption, but not all.

If it was plausible that the suspect might not know how to decrypt the file, that would make things even more interesting. For now, the moral of the story is that you can’t rely on the Fifth Amendment to protect you from contempt of court charges in the United States if you try to protect your encrypted data. Outside the US, your mileage may vary.

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Cnet reports that an internal DEA document reveals that the DEA are unable to intercept text messages sent over Apple’s iMessage protocol.

The protocol provides end to end encryption for messages between iOS and Mac OS X devices.

This is not to suggest that the encryption in iMessages is particularly good, but to contrast with standard text messages and voice calls which are completely unprotected within the phone company’s networks.

It appears that an active man in the middle attack would be able to thwart the encryption, but would be significantly more effort. The lack of any kind of out of band channel authentication suggests that such an attack should not be too difficult.

If you really need to protect your chat messages, I suggest using a tool like Silent Text. They take some steps that make man in the middle attacks almost impossible.

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Jan/11

25

Specter of Mandatory Data Retention

In this CNET article by Declan McCulagh, he reports that the DoJ is planning to request mandatory data retention by Internet providers. Their argument is that the lack of data retention is interfering with law enforcement’s ability to investigate cases. This implies some kind of shift in the balance of privacy vs. access. No such shift has taken place.

I think that they are more frustrated by the fact that a huge potential gold mine of information is out there to which they don’t have access. Prior to the various modern technological revolutions people used pay phones, sent letters, and paid cash for toll roads.

Now they use Twitter, SMS, Facebook, Email, cell phones, electronic toll payment etc. There is way more information available to law enforcement now than before. The fact that this data retention is only on the Internet may make people feel better, but one would certainly learn more about me from my Internet activities than from following me around physically.

Lets look at what is being asked for with a real world analogy. This is like saying that the US Postal Service should photograph and database the address, and return address, on every letter which goes through the system. Physically is it like saying the cell phone company should record and retain my GPS location at all times. Either of those would actually be much less intrusive than monitoring how I use the Internet at all times.

Lets not get in to the cost of maintaining these records or the issues with leaks or hackers. Consider the Chinese attacks on dissident Google accounts. This plan would ensure that such information was much more widely maintained.

At this point it appears to be a only a request. I am curious to see how this evolves over the congressional term.

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The EFF has an excellent article on eight reasons why government regulation of cryptography is a bad idea.

The short answer is: the bad guys can easily get it and use it anyway, and it will make security for the rest of us much worse (not including the big brother surveillance  and constitutional issues).

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