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So far the tech press pretty much unanimously touts advances in LTE Carrier Aggregation as a way to further increase data rates for customers. With 2×20 MHz Carrier Aggregation a 2×2 MIMO network can be pushed to theoretical peak data rates of 300 MBit/s. 3CA pushes the limit to a theoretical 450 MBit/s and 4×4 MIMO and 256 QAM modulation pushes the limit even further. From my point of view, however, the main benefit of Carrier Aggregation lies elsewhere.

Continue reading LTE CA Not For Speed But To Address Rising Demand

… the PIN.

Today I read in the news that a smartphone manufacturer has received a “friendly” invitation letter from US law enforcement that asks them to help decrypting a phone of a terrorist that is encrypted. The encryption key itself is protected with the PIN that the user has to type in and software that keeps increasing the delay between two guessing attempts. I am sure the company sympathizes with the general idea of decrypting a device of a terrorist but sees itself unable to comply with the request as this would also significantly weaken security and privacy for the rest of us. If the let someone do it with that phone it can be done with others, too. Once in the wild…

While most of the media is discussing the pros and cons of the move there is a deeper issue here that nobody seems to think about: A simple 4 or 6 digit pin and a bit of software should not protect the ciphering key in the first place.

Continue reading And The Weakest Link In Mobile Security Is…

After moving from Typepad to my own WordPress installation, search engines haven’t yet caught up with the change. As a consequence most of the traffic is from regular readers who have updated their bookmarks and RSS feeds after reading about the move from the old site. So before traffic referred to my blog by search engines is increasing I made a snapshot of current statistics to see if regular readers use a different mix of browsers, operating systems and connectivity.

Continue reading Blog Statistics – The First Weeks

When Thalys started to offer Wifi service in 2009 on their trains in Europe I was ecstatic as it was working great. Over the years however, their service deteriorated to something barely usable (see here, here and here) and has remained so ever since. In contrast to their service, Internet access on high speed trains in Germany has remained mostly usable over the years. Instead of satellites, Deutsche Bahn (DB) has been using a dedicated cellular network along the railway lines and has upgraded to UMTS and LTE over the years to increase capacity. So far, the service was not free so the number of users was limited and the network has remained usable. Now, however, driven by national politics who is looking for quick and simple answers, DB needs to upgrade the system and offer it for free to all passengers. A recipe for disaster?

Continue reading I Like Free Wifi on The Train – But Would I rather want to Pay for it?

A thing I was not aware about embedding Youtube videos so far was that even when visitors do not click on the video, they are already tracked by Google. Visiting the page in which the video is embedded is enough to get tracked. But it doesn’t have to be that way as there’s a “privacy enhanced” way to embed Youtube videos.

Continue reading Privacy Enhanced Youtube Embedding

When I recently configured a computer for Eduroam access in Vienna I took the opportunity to have a quick look at what’s in the air in Vienna University’s main reading room. It turned out that it was much more than I thought. In short, they use pretty much ALL available spectrum in the 2.4 and 5 GHz bands:

Continue reading 320 MHz of Wifi In Univiersity of Vienna’s Main Reading Hall

I was more than a bit annoyed when I noticed that whenever I restart the browser and load my website, the browser reaches out to Google to load a number of font files. What!?

Continue reading Removing Google Fonts On This Blog

Over the past years I’ve explored many ways how to combine my memories of computing of the 1980’s with my quest to better understand how a CPU works and using contemporary technology for the purpose. Here’s another cool approach to do this by emulating a Busch 2090 4-bit computer on an Arudino.

Continue reading A Busch 2090 Emulator on an Arduino

It’s been a while since I switched the final Windows based machine to Linux at my place. Admittedly there are a few things I still need Windows for but those can comfortably run in a Virtual machine on a Linux host or by using Wine, the Windows Emulation Layer for Linux. But time has come to go a step further once again.

Continue reading Uninstalling Wine – Bye Bye Windows Emulation Layer

Back in December 2015 I found my first public Wifi network at 32C3 that used a certificate instead of a common password, not so much for user authentication but for assigning an individual ciphering key to each device. Especially at a hacker conference that’s a plus as normal WPA encryption uses the same passphrase for everyone and hence attackers can decrypt the Wifi traffic of others if they know the common passphrase and have intercepted the authentication dialog. When recently being asked to configure a computer for Eduroam access, an international Wifi network at universities (for a world map see here), I found yet another flavor of Wifi certificate use that is highly interesting.

Continue reading Eduroam – Wifi With A Certificate And Cool Roaming Features