Entries Tagged "concealment"

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Analysis of Printer Watermarking Techniques

Interesting paper: Maya Embar, Louis M. McHough IV, and William R. Wesselman, “Printer watermark obfuscation,” Proceeding
RIIT ’14: Proceedings of the 3rd annual conference on Research in information technology
:

Abstract: Most color laser printers manufactured and sold today add “invisible” information to make it easier to determine when a particular document was printed and exactly which printer was used. Some manufacturers have acknowledged the existence of the tracking information in their documentation while others have not. None of them have explained exactly how it works or the scope of the information that is conveyed. There are no laws or regulations that require printer companies to track printer users this way, and none that prevent them from ceasing this practice or providing customers a means to opt out of being tracked. The tracking information is coded by patterns of yellow dots that the printers add to every page they print. The details of the patterns vary by manufacturer and printer model.

EDITED TO ADD (11/14): List of printers and whether or not they display tracking dots (may not be up to date).

Posted on October 24, 2014 at 8:36 AMView Comments

StealthGenie CEO Indicted

StealthGenie is a Pakistani company that sells a smartphone app that allows a remote party to monitor the phone. The CEO was just indicted in the US:

“Selling spyware is not just reprehensible, it’s a crime,” Leslie Caldwell, assistant attorney general in the DOJ’s Criminal Division, said in a statement. “Apps like StealthGenie are expressly designed for use by stalkers and domestic abusers who want to know every detail of a victim’s personal life—all without the victim’s knowledge.”

This is likely to be a big deal. The company should have sold the spyware only to governments. That would have been okay.

Posted on October 1, 2014 at 10:48 AMView Comments

The Simple Trick that Will Keep You Secure from Government Spies

Last week, the German government arrested someone and charged him with spying for the US. Buried in one of the stories was a little bit of tradecraft. The US gave him an encryption program embedded in a—presumably common—weather app. When you select the weather for New York, it automatically opens a crypto program. I assume this is a custom modification for the agent, and probably other agents as well. No idea how well this program was hidden. Was the modified weather app the same size as the original? Would it pass an integrity checker?

Related: there is an undocumented encryption feature in my own Password Safe program. From the command line, type: pwsafe -e filename

Posted on July 7, 2014 at 1:51 PMView Comments

Adware Vendors Buy and Abuse Chrome Extensions

This is not a good development:

To make matters worse, ownership of a Chrome extension can be transferred to another party, and users are never informed when an ownership change happens. Malware and adware vendors have caught wind of this and have started showing up at the doors of extension authors, looking to buy their extensions. Once the deal is done and the ownership of the extension is transferred, the new owners can issue an ad-filled update over Chrome’s update service, which sends the adware out to every user of that extension.

[…]

When malicious apps don’t follow Google’s disclosure policy, diagnosing something like this is extremely difficult. When Tweet This Page started spewing ads and malware into my browser, the only initial sign was that ads on the Internet had suddenly become much more intrusive, and many auto-played sound. The extension only started injecting ads a few days after it was installed in an attempt to make it more difficult to detect. After a while, Google search became useless, because every link would redirect to some other webpage. My initial thought was to take an inventory of every program I had installed recently—I never suspected an update would bring in malware. I ran a ton of malware/virus scanners, and they all found nothing. I was only clued into the fact that Chrome was the culprit because the same thing started happening on my Chromebook—if I didn’t notice that, the next step would have probably been a full wipe of my computer.

Posted on January 21, 2014 at 6:33 AMView Comments

Operation Vula

Talking to Vula” is the story of a 1980s secret communications channel between black South African leaders and others living in exile in the UK. The system used encrypted text encoded into DTMF “touch tones” and transmitted from pay phones.

Our next project was one that led to the breakthrough we had been waiting for. We had received a request, as members of the Technical Committee, to find a way for activists to contact each other safely in an urban environment. Ronnie had seen a paging device that could be used between users of walkie-talkies. A numeric keypad was attached to the front of each radio set and when a particular number was pressed a light would flash on the remote set that corresponded to the number. The recipient of the paging signal could then respond to the caller using a pre-determined frequency so that the other users would not know about it.

Since the numbers on the keypad actually generated the same tones as those of a touch-tone telephone it occurred to us that instead of merely having a flashing light at the recipient`s end you could have a number appear corresponding to the number pressed on the keypad. If you could have one number appear you could have all numbers appear and in this way send a coded message. If the enemy was monitoring the airwaves all they would hear was a series of tones that would mean nothing.

Taking this a step further we realised that if you could send the tones by radio then they could also be sent by telephone, especially as the tones were intended for use on telephone systems. Ronnie put together a little microphone device that – when held on the earpiece of the receiving telephone – could display whatever number was pressed at the sending end. Using touch-tone telephones or separate tone pads as used for telephone banking services two people could send each other coded messages over the telephone. This could be done from public telephones, thus ensuring the safety of the users.

To avoid having to key in the numbers while in a telephone booth the tones could be recorded on a tape recorder at home and then played into the telephone. Similarly, at the receiving end, the tones could be recorded on a tape recorder and then decoded later. Messages could even be sent to an answering machine and picked up from an answering machine if left as the outgoing message.

We gave a few of these devices, disguised as electronic calculators, to activists to take back to South Africa. They were not immensely successful as the coding still had to be done by hand and that remained the chief factor discouraging people from communicating.

The next step was an attempt to marry the tone communication system with computer encryption. Ronnie got one of the boffins at the polytechnic to construct a device that produced the telephone tones at very high speed. This was attached to a computer that did the encryption. The computer, through the device, output the encrypted message as a series of tones and these could be saved on a cassette tape recorder that could be taken to a public telephone. This seemed to solve the problem of underground communications as everything could be done from public telephones and the encryption was done by computer.

Lots more operational details in the article.

Posted on December 26, 2013 at 6:44 AMView Comments

WhoIs Privacy and Proxy Service Abuse

ICANN has a draft study that looks at abuse of the Whois database.

This study, conducted by the National Physical Laboratory (NPL) in the United Kingdom, analyzes gTLD domain names to measure whether the percentage of privacy/proxy use among domains engaged in illegal or harmful Internet activities is significantly greater than among domain names used for lawful Internet activities. Furthermore, this study compares these privacy/proxy percentages to other methods used to obscure identity ­ notably, Whois phone numbers that are invalid.

Richard Clayton, the primary author of the report, has a blog post:

However, it’s more interesting to ask whether this percentage is somewhat higher than the usage of privacy or proxy services for entirely lawful and harmless Internet activities? This turned out NOT to be the case ­ for example banks use privacy and proxy services almost as often as the registrants of domains used in the hosting of child sexual abuse images; and the registrants of domains used to host (legal) adult pornography use privacy and proxy services more often than most (but not all) of the different types of malicious activity that we studied.

Richard has been telling me about this work for a while. It’s nice to see it finally published.

Posted on October 1, 2013 at 9:09 AMView Comments

Evading Internet Censorship

This research project by Brandon Wiley—the tool is called “Dust”—looks really interesting. Here’s the description of his Defcon talk:

Abstract: The greatest danger to free speech on the Internet today is filtering of traffic using protocol fingerprinting. Protocols such as SSL, Tor, BitTorrent, and VPNs are being summarily blocked, regardless of their legal and ethical uses. Fortunately, it is possible to bypass this filtering by reencoding traffic into a form which cannot be correctly fingerprinted by the filtering hardware. I will be presenting a tool called Dust which provides an engine for reencoding traffic into a variety of forms. By developing a good model of how filtering hardware differentiates traffic into different protocols, a profile can be created which allows Dust to reencode arbitrary traffic to bypass the filters.

Dust is different than other approaches because it is not simply another obfuscated protocol. It is an engine which can encode traffic according to the given specifications. As the filters change their algorithms for protocol detection, rather than developing a new protocol, Dust can just be reconfigured to use different parameters. In fact, Dust can be automatically reconfigured using examples of what traffic is blocked and what traffic gets through. Using machine learning a new profile is created which will reencode traffic so that it resembles that which gets through and not that which is blocked. Dust has been created with the goal of defeating real filtering hardware currently deployed for the purpose of censoring free speech on the Internet. In this talk I will discuss how the real filtering hardware work and how to effectively defeat it.

EDITED TO ADD (9/11): Papers about Dust. Dust source code.

Posted on August 28, 2013 at 7:07 AMView Comments

Detaining David Miranda

Last Sunday, David Miranda was detained while changing planes at London Heathrow Airport by British authorities for nine hours under a controversial British law—the maximum time allowable without making an arrest. There has been much made of the fact that he’s the partner of Glenn Greenwald, the Guardian reporter whom Edward Snowden trusted with many of his NSA documents and the most prolific reporter of the surveillance abuses disclosed in those documents. There’s less discussion of what I feel was the real reason for Miranda’s detention. He was ferrying documents between Greenwald and Laura Poitras, a filmmaker and his co-reporter on Snowden and his information. These document were on several USB memory sticks he had with him. He had already carried documents from Greenwald in Rio de Janeiro to Poitras in Berlin, and was on his way back with different documents when he was detained.

The memory sticks were encrypted, of course, and Miranda did not know the key. This didn’t stop the British authorities from repeatedly asking for the key, and from confiscating the memory sticks along with his other electronics.

The incident prompted a major outcry in the UK. The UK’s Terrorist Act has always been controversial, and this clear misuse—it was intended to give authorities the right to detain and question suspected terrorists—is prompting new calls for its review. Certainly the UK. police will be more reluctant to misuse the law again in this manner.

I have to admit this story has me puzzled. Why would the British do something like this? What did they hope to gain, and why did they think it worth the cost? And—of course—were the British acting on their own under the Official Secrets Act, or were they acting on behalf of the United States? (My initial assumption was that they were acting on behalf of the US, but after the bizarre story of the British GCHQ demanding the destruction of Guardian computers last month, I’m not sure anymore.)

We do know the British were waiting for Miranda. It’s reasonable to assume they knew his itinerary, and had good reason to suspect that he was ferrying documents back and forth between Greenwald and Poitras. These documents could be source documents provided by Snowden, new documents that the two were working on either separately or together, or both. That being said, it’s inconceivable that the memory sticks would contain the only copies of these documents. Poitras retained copies of everything she gave Miranda. So the British authorities couldn’t possibly destroy the documents; the best they could hope for is that they would be able to read them.

Is it truly possible that the NSA doesn’t already know what Snowden has? They claim they don’t, but after Snowden’s name became public, the NSA would have conducted the mother of all audits. It would try to figure out what computer systems Snowden had access to, and therefore what documents he could have accessed. Hopefully, the audit information would give more detail, such as which documents he downloaded. I have a hard time believing that its internal auditing systems would be so bad that it wouldn’t be able to discover this.

So if the NSA knows what Snowden has, or what he could have, then the most it could learn from the USB sticks is what Greenwald and Poitras are currently working on, or thinking about working on. But presumably the things the two of them are working on are the things they’re going to publish next. Did the intelligence agencies really do all this simply for a few weeks’ heads-up on what was coming? Given how ham-handedly the NSA has handled PR as each document was exposed, it seems implausible that it wanted advance knowledge so it could work on a response. It’s been two months since the first Snowden revelation, and it still doesn’t have a decent PR story.

Furthermore, the UK authorities must have known that the data would be encrypted. Greenwald might have been a crypto newbie at the start of the Snowden affair, but Poitras is known to be good at security. The two have been communicating securely by e-mail when they do communicate. Maybe the UK authorities thought there was a good chance that one of them would make a security mistake, or that Miranda would be carrying paper documents.

Another possibility is that this was just intimidation. If so, it’s misguided. Anyone who regularly reads Greenwald could have told them that he would not have been intimidated—and, in fact, he expressed the exact opposite sentiment—and anyone who follows Poitras knows that she is even more strident in her views. Going after the loved ones of state enemies is a typically thuggish tactic, but it’s not a very good one in this case. The Snowden documents will get released. There’s no way to put this cat back in the bag, not even by killing the principal players.

It could possibly have been intended to intimidate others who are helping Greenwald and Poitras, or the Guardian and its advertisers. This will have some effect. Lavabit, Silent Circle, and now Groklaw have all been successfully intimidated. Certainly others have as well. But public opinion is shifting against the intelligence community. I don’t think it will intimidate future whistleblowers. If the treatment of Chelsea Manning didn’t discourage them, nothing will.

This leaves one last possible explanation—those in power were angry and impulsively acted on that anger. They’re lashing out: sending a message and demonstrating that they’re not to be messed with—that the normal rules of polite conduct don’t apply to people who screw with them. That’s probably the scariest explanation of all. Both the US and UK intelligence apparatuses have enormous money and power, and they have already demonstrated that they are willing to ignore their own laws. Once they start wielding that power unthinkingly, it could get really bad for everyone.

And it’s not going to be good for them, either. They seem to want Snowden so badly that that they’ll burn the world down to get him. But every time they act impulsively aggressive—convincing the governments of Portugal and France to block the plane carrying the Bolivian president because they thought Snowden was on it is another example—they lose a small amount of moral authority around the world, and some ability to act in the same way again. The more pressure Snowden feels, the more likely he is to give up on releasing the documents slowly and responsibly, and publish all of them at once—the same way that WikiLeaks published the US State Department cables.

Just this week, the Wall Street Journal reported on some new NSA secret programs that are spying on Americans. It got the information from “interviews with current and former intelligence and government officials and people from companies that help build or operate the systems, or provide data,” not from Snowden. This is only the beginning. The media will not be intimidated. I will not be intimidated. But it scares me that the NSA is so blind that it doesn’t see it.

This essay previously appeared on TheAtlantic.com.

EDITED TO ADD: I’ve been thinking about it, and there’s a good chance that the NSA doesn’t know what Snowden has. He was a sysadmin. He had access. Most of the audits and controls protect against normal users; someone with root access is going to be able to bypass a lot of them. And he had the technical chops to cover his tracks when he couldn’t just evade the auditing systems.

The AP makes an excellent point about this:

The disclosure undermines the Obama administration’s assurances to Congress and the public that the NSA surveillance programs can’t be abused because its spying systems are so aggressively monitored and audited for oversight purposes: If Snowden could defeat the NSA’s own tripwires and internal burglar alarms, how many other employees or contractors could do the same?

And, to be clear, I didn’t mean to say that intimidation wasn’t the government’s motive. I believe it was, and that it was poorly thought out intimidation: lashing out in anger, rather than from some Machiavellian strategy. (Here’s a similar view.) If they wanted Miranda’s electronics, they could have confiscated them and sent him on his way in fifteen minutes. Holding him for nine hours—the absolute maximum they could under the current law—was intimidation.

I am reminded of the phone call the Guardian received from British government. The exact quote reported was: “You’ve had your fun. Now we want the stuff back.” That’s something you would tell your child. And that’s the power dynamic that’s going on here.

EDITED TO ADD (8/27): Jay Rosen has an excellent essay on this.

EDITED TO ADD (9/12): Other editors react.

Posted on August 27, 2013 at 6:39 AMView Comments

Musing on Secret Languages

This is really interesting. It starts by talking about a “cant” dictionary of 16th-century thieves’ argot, and ends up talking about secret languages in general.

Incomprehension breeds fear. A secret language can be a threat: signifier has no need of signified in order to pack a punch. Hearing a conversation in a language we don’t speak, we wonder whether we’re being mocked. The klezmer-loshn spoken by Jewish musicians allowed them to talk about the families and wedding guests without being overheard. Germanía and Grypsera are prison languages designed to keep information from guards—the first in sixteenth-century Spain, the second in today’s Polish jails. The same logic shows how a secret language need not be the tongue of a minority or an oppressed group: given the right circumstances, even a national language can turn cryptolect. In 1680, as Moroccan troops besieged the short-lived British city of Tangier, Irish soldiers manning the walls resorted to speaking as Gaeilge, in Irish, for fear of being understood by English-born renegades in the Sultan’s armies. To this day, the Irish abroad use the same tactic in discussing what should go unheard, whether bargaining tactics or conversations about taxi-drivers’ haircuts. The same logic lay behind North African slave-masters’ insistence that their charges use the Lingua Franca (a pidgin based on Italian and Spanish and used by traders and slaves in the early modern Mediterranean) so that plots of escape or revolt would not go unheard. A Flemish captive, Emanuel d’Aranda, said that on one slave-galley alone, he heard “the Turkish, the Arabian, Lingua Franca, Spanish, French, Dutch, and English.” On his arrival at Algiers, his closest companion was an Icelander. In such a multilingual environment, the Lingua Franca didn’t just serve for giving orders, but as a means of restricting chatter and intrigue between slaves. If the key element of the secret language is that it obscures the understandings of outsiders, a national tongue can serve just as well as an argot.

Posted on July 10, 2013 at 5:55 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.