cybersecurity

31 Articles

Lock Up Your Raspberry Pi With Google Authenticator

September 30, 2016 by 14 Comments

Raspberry Pi boards (or any of the many similar boards) are handy to leave at odd places to talk to the network and collect data, control things, or do whatever other tasks you need a tiny fanless computer to do. Of course, any time you have a computer on a network, you are inviting hackers (and not our kind of hackers) to break in.

We recently looked at how to tunnel ssh using a reverse proxy via Pagekite so you can connect to a Pi even through firewalls and at dynamic IP addresses. How do you stop a bad guy from trying to log in repeatedly until they have access? This can work on any Linux machine, but for this tutorial I’ll use Raspberry Pi as the example device. In all cases, knowing how to set up adequate ssh security is paramount for anything you drop onto a network.

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Bridging The Air Gap; Data Transfer Via Fan Noise

July 1, 2016 by 45 Comments

When you want to protect a computer connected to the Internet against attackers, you usually put it behind a firewall. The firewall controls access to the protected computer. However, you can defeat any lock and there are ways a dedicated attacker can compromise a firewall. Really critical data is often placed on a computer that is “air gapped.” That is, the computer isn’t connected at all to an insecure network.

An air gap turns a network security problem into a physical security problem. Even if you can infect the target system and collect data, you don’t have an easy way to get the data out of the secure facility unless you are physically present and doing something obvious (like reading from the screen into a phone). Right? Maybe not.

Researchers in Isreal have been devising various ways to transmit data from air walled computers. Their latest approach? Transmit data via changing the speed of cooling fans in the target computer. Software running on a cellphone (or other computer, obviously) can decode the data and exfiltrate it. You can see a video on the process below.

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Apple Aftermath: Senate Entertains A New Encryption Bill

April 11, 2016 by 62 Comments

If you recall, there was a recent standoff between Apple and the U. S. Government regarding unlocking an iPhone. Senators Richard Burr and Dianne Feinstein have a “discussion draft” of a bill that appears to require companies to allow the government to court order decryption.

Here at Hackaday, we aren’t lawyers, so maybe we aren’t the best source of legislative commentary. However, on the face of it, this seems a bit overreaching. The first part of the proposed bill is simple enough: any “covered entity” that receives a court order for information must provide it in intelligible form or provide the technical assistance necessary to get the information in intelligible form. The problem, of course, is what if you can’t? A covered entity, by the way, is anyone from a manufacturer, to a software developer, a communications service, or a provider of remote computing or storage.

There are dozens of services (backup comes to mind) where only you have the decryption keys and there is nothing reasonable the provider can do to get your data if you lose your keys. That’s actually a selling point for their service. You might not be anxious to backup your hard drive if you knew the vendor could browse your data when they wanted to do so.

The proposed bill has some other issues, too. One section states that nothing in the document is meant to require or prohibit a specific design or operating system. However, another clause requires that covered entities provide products and services that are capable of complying with the rule.

A broad reading of this is troubling. If this were law, entire systems that don’t allow the provider or vendor to decrypt your data could be illegal in the U. S. Whole classes of cybersecurity techniques could become illegal, too. For example, many cryptography systems use the property of forward secrecy by generating unrecorded session keys. For example, consider an SSH session. If someone learns your SSH key, they can listen in or interfere with your SSH sessions. However, they can’t take recordings of your previous sessions and decode them. The mechanism is a little different between SSHv1 (which you shouldn’t be using) and SSHv2. If you are interested in the gory details for SSHv2, have a look at section 9.3.7 of RFC 4251.

In all fairness, this isn’t a bill yet. It is a draft and given some of the definitions in section 4, perhaps they plan to expand it so that it makes more sense, or – at least – is more practical. If not, then it seems to be an indication that we need legislators that understand our increasingly technical world and have some understanding of how the new economy works. After all, we’ve seen this before, right? Many countries are all too happy to enact and enforce tight banking privacy laws to encourage deposits from people who want to hide their money. What makes you think that if the U. S. weakens the ability of domestic companies to make data private, that the business of concealing data won’t just move offshore, too?

If you were living under a rock and missed the whole Apple and FBI controversy, [Elliot] can catch you up. Or, you can see what [Brian] thought about Apple’s response to the FBI’s demand.