In 2015 the FBI wanted to hack the iPhone of a terrorist, highlighting the Crypto Wars: the authorities have fight for more power, and the defenders of computer privacy become increasingly good at securing information against unwanted spies.

But privacy on the internet is not only important for terrorists, but also highly valued by the ‘normal users’. A lot of websites already help people to encrypt their messages by giving every visiting computer a unique key. These keys are hard to retrieve and hard to crack, causing a lot of hackers to stay clear. But in spite of the encryption, users are still traceable, and thus never really anonymous. This is because the destination of a message has to stay readable in order for it to reach its destination.

In 1981 David Chaum came up with an idea to solve this problem: Tor. Tor consists of a network of computers, enabled by volunteers from around the world. If a user contacts someone, Tor randomly chooses three of these computers called nodes. The sender encrypts each message three times, before it sends the message to the first computer. This computer peels off the outer encryption layer and sends the message on to the second computer. This is process is continued until the message reaches its destination. If spyware were to hack one of the nodes, it could find out either the sender or the recipient, but never both. In order to know both sides of the communication, all nodes should be hacked, and since these are three random computers out of a huge network, this is an almost impossible job. But, also this system has its downsides: it is quite slow, the nodes are normal computers (i.e. not super secure), the message can still be traced by matching the times messages are sent and received and the encryption doesn’t change the length of the sent message, causing it to be recognizable.

To correct these downsides, Chaum came up with the idea for cMix-network in 2016. In the cMix-network, the nodes are exchanged for around ten servers in datacenters, all in different countries with good privacy regulations. The differences with Tor are:

• The nodes are always the same servers, used in the same order, but hacking the servers is a lot harder than hacking one of the computers that is used for Tor;
• The sender must complement its message to meet the standard length, causing it to be unrecognizable;
• The message has 10 encryption layers instead of 3;
• The message is sent to the network where it is coupled with a standard amount of other messages, mixing the order of messages, to form a batch. This means that the messages have to wait for some amount milliseconds, making it harder to match the times messages are sent and received;
• The system is faster because the servers make encryption codes in advance, when there is little traffic to keep them busy.

Because of the Crypto Wars, Chaum also came up with PrivaTegrity, in which the anonymity of criminals can be taken away. This network consists of nine servers in different countries. If the administrators of these servers unanimously decide that a person must be traced, they can do so, and all the servers will communicate with each other to reconstruct the complete path a message has traveled. Which problems do you see with this idea? Would it be a good idea to use a system like PrivaTegrity? Or should we keep using systems like Tor and cMix?

Sources:

Können, T. (2016). Gemixte berichten. De ingenieur. 128 (7), 26-28.

Chaum, D. (2016). cMix: Anonymization by High-Performance Scalable Mixing. 1-16.

Back in the days, before smartphones, navigating to a new place was always a struggle that more often than not resulted in me being lost in the middle of nowhere. Without a sense of direction this is bad news. In 2006 I entered heaven. I got a smartphone that gave me the exact directions and my problem was solved. Or so I thought. Until I went somewhere by bike. Looking at the screen while cycling wasn’t a good idea which meant I had to stop every 2 minutes to check my directions. Not ideal, to say the least. So you can imagine my joy when I found out about Lechal, a smart device that you can mount in the insoles of your footwear and that can give directions using vibratory or haptic signals.

Once you place Lechal in your footwear, you can connect it to an app using Bluetooth. The app allows for turn-by-turn navigation, while walking, cycling or driving. In order to guide you from your current location to your destination, the shoes vibrate to let you know when and where to. The left shoe for a left turn, and the right for a right turn. And it even works offline, so finding your way in another country will be easier than ever before. Without a map in your hand, finally no one will suspect that you are a tourist. In addition to navigation, Lechal can be used as a fitness tracking system by counting your steps, tracking the amount of calories burned, and creating interactive workouts. Lechal can also vibrate when you leave your phone behind or if you are passing a point of interest.

As far as I know, there is already one other wearable navigation technology, the navigate jacket. The navigate jacket has LED lights on the sleeves that light up to indicate a left or right turn. Since this is a very visible form of navigation, being an undercover tourist will still not be one of your options.

What do you think about Lechal? Would you buy it?

Promotional video as a demonstration

Source: http://www.lechal.com/