Krehn Solutions


Category: News
Published on Thursday, 13 August 2015
Written by Raymond Krehn

Note: Recommendations are at the bottom if you want to skip this article.

I came across an easily one-sided article that states in the opening statement, "The use of ad-blocking software is exploding and is projected to cost websites nearly $22 billion in lost advertising revenue worldwide this year, according to a new study." Without going into semantics about the definition of cost, what this article should really state is that ad-blocking software projects to reduce potential revenue by $22 billion worldwide this year. The key difference here is the costs haven't incurred yet and it's only potential income.

I can understand the problem from a business perspective: You provide free content for users and you need to pay the bills and ad space will help pay your bills. It's simply logic. Even Mozilla, the developers behind Firefox have stated that they plan to implement ads in their browser to help pay the bills. But, we also need to consider the users too. Take a look at Denver Post, for example. I won't link there, because I will spare you the pain with a screenshot.


Denver Post with Ads

Let's get one thing straight: Denver Post is a news site. Why is 90% of the page that I open up ads unrelated to news? Let alone I have zero interest in guns. The problem, my dearest business industry, is you. I have no problem opening up a website and seeing an ad on the corner of a site. I can see it. It's definitely there. implements this very well. What I don't want to see is my example above. When you're ruining user's experience then you are to blame on your lost revenue. In fact, it is so bad that a study done at Simon Fraser University notes "Computers running the Adblock Plus browser extension saw a 25.0% decrease in associated total data usage during web-browsing sessions." That's excluding videos. Including videos, "testing revealed a 40.0% decrease in total data usage." 

We're beginning to live in a world with bandwidth caps for data. Comcast has a limit of 250gb per month, and many cell phone companies like Verizon and AT&T are much worse with an average data limit of 2GB. 25% reduction of data usage is half a gig that could be better used for streaming music or using maps to help you get unlost. 

Until the industry listens to the user, I highly recommend ad-blocking software. But, my reasons for utilizing it go far beyond bandwidth usage. Many sites that have advertisements don't even know what their own ads are displaying. They're using various vendors like Google Adwords to select ads for them. Let's take a look at one below:

Malware ad

A user captured this on a popular site called Dailymotion, a video-sharing service similar to Youtube or Liveleaks. The ad seems legitimate at first. It informs you that you have spyware detected on your computer and clicking that big button it will help remove it. Instead, it will install malware on your computer. The spyware it was referring to is itself. 

Furthermore, you have dynamic pricing where some sites will alter prices based on varying data such as your personal spending habits, your location, your age, and more. I can attest to this personally. For a flight for two in early July I was given a quote by Southwest Airlines for $537. I didn't purchase the tickets immediately because I wanted to confirm various factors in the decision. About an hour later I went back to purchase the tickets and they had move up to $780. At first I thought it was a supply and demand thing so I checked on my phone. The price on my mobile phone was slightly more than the first price, but not much. The article I linked to about dynamic pricing talks about the pricing differences on Amazon depending on location. Needless to say, it's unfair for the consumer to be judged based on their search history or any of these other factors.



Using one of these options or all of them will drastically improve your webbrowsing experience. Happy browsing!


My SSD is near capacity. What can I do?

Category: News
Published on Saturday, 27 June 2015
Written by Raymond Krehn

I see this question a lot and it actually bothered me that my 120 GB Solid State Drive (SSD) was near full capacity despite the fact I install almost everything on a secondary drive. I try to keep only my Windows installation on the SSD for incredibly fast boot times. If you're unfamiliar with the SSD, here's a simple comparison with the same computer by ASUS:

SSD is the new up-and-coming technology for data storage. Unlike the regular hard drive that most people have, it doesn't use a disk and thus no spin motor. It simply uses integrated circuits, so it makes it much faster than the HD.

Ever since the horrible Windows Vista, Microsoft has stored backups, restore points, and installers into your computer. This isn't necessarily bad. Backups and restore points are very useful if you have a virus or after an update the computer becomes unusable. Installers are the same thing, just at an application level. If you want to keep any of this information, then you should only do section A of this article and ignore section B.

Section A

  1. The first step would be to try Disk Cleanup utility automatically included in Windows. Go ahead and click that link to a wonderful tutorial by Microsoft.
  2. The next option is using CCleaner (Crap Cleaner). Don't worry, it's free, but you can upgrade if you really want to. This software searches your computer for data files no longer needed, temporary files, duplicate files, amongst other... well, crap. They have a wonderful tutorial series if you need it. 
  3. What about defragmentation? This only works for hard drives. Defragmentation moves information that is needed towards the middle since disks spin faster there. It moves unneeded files towards the edge. Since SSD's don't have a disk, this has no use!

Section B

I highly recommend downloading a disk size scanning software like WinDirStat (also free) to help dive deep into what is causing data consumption. Many of you will find two folders of interest in particular: winsxs and Installer under the Windows directory.

I got bad news and good news for you. The good news is that both of these directories can be moved. The bad news is that you probably shouldn't. Remember how I mentioned earlier about Microsoft referencing installation files and what not for backups? Well if that information is gone, how will you backup anything?

However, Microsoft does have some fancy linking technology that we can take advantage of. We can basically force Windows to believe that those files and folders are there even if they're not. I'll start with Installer:

  1. Start off by creating a backup folder on another drive. For this example, I named mine D:\Backups\Installer
  2. Open command prompt 
  3. Type: "robocopy C:\Windows\Installer D:\Backups\Installer" - The second directory should be your backup folder. Hit enter.
    Robocopy is a neat Microsoft built utility that copies massive amounts of files almost instantly
  4. When that's done, type: "mklink C:\Windows\Installer D:\Backups\Installer" (or the backup folder) and hit enter.
    This nice feature is creating the actual link so Windows thinks that the installation files are where they should be
  5. You may now delete the C:\Windows\Installer folder

Now you will notice a huge amount of capacity restored to your SSD. But, what about winsxs folder? I highly don't recommend it. It is possible, however. While you have WinDirStat open, I would recommend digging into other folders you may not find necessary, especially those under Users first. Typically, there is a lot of temporary stored data in the Users\AppData folder. CCleaner should've cleaned some of this stuff if you ran it beforehand.

I hope this helps!

Password Manager LastPass Security Breach

Category: News
Published on Tuesday, 16 June 2015
Written by Raymond Krehn

 "LastPass, a company that offers users a way to centrally manage all of their passwords online with a single master password, disclosed Monday that intruders had broken into its databases and made off with user email addresses and password reminders, among other data."

But, you probably shouldn't worry too much. LastPass utilizes AES 256-bit encryption on your device with the lastest PBKDF2 algorithms. I'll go more in-depth of these shortly, but what you really need to know is that since the data is encrypted on your device, by the time it arrives on the LastPass servers in what they call a vault, they don't even know what your passwords are. They'll need to know your salt encryption key to even begin exposing your password. Before this, however, anyone looking at your passwords will need to know your master password, which is also encrypted. If you have two-way authentication, you'll have to approve their access to your vault. 

Can you explain these terms?

I first started talking about AES 256-bit encryption. AES stands for Advanced Encryption Standard and 256-bit is the block size (length of data). Block sizes can come in a variety of numbers like 128 or 192, as long as it's a 32-bit number (multiple of 32). As with most things, the higher the number the better. Since LastPass uses 256-bit, it takes advantage of 14 cycle repetitions where it replaces one key with another key. So imagine the letter "a" being changed to another letter like "b" and "c", only 14 times. So what determines what letter it gets replaced with? Your master password, which only you (should) know. The video below shows an example of this in detail.

What's PBKDF2 and what does it have to do with salt?

PBKDF2 stands for Password-Based Key Derivation Function 2. It is a pseudorandom number that takes the input of your salt and the password to create a derived key. Salt, then, is a completely random number that alters your password through a system we call hashing (more terms, I know). Salts make using a using a dictionary of pre-determined encrypted passwords, called a rainbow table, more difficult. The primary purpose behind a hash function is to mix up your password to make it look like it isn't a valid word. So a hash function will mix a randomly generated number (salt) and merge it with your master password, thus making your password rather difficult to read if the person looking at it doesn't have both the salt and password. However, it's not impossible. A person with the right rainbow table (basically translation dictionary of your hash) can still figure out your password. With enough processing power it may only take a few years. This is where PBKDF2 becomes useful. It requires both the salt and password, plus additional iterations to be created. Here's an example of one:

DK = PBKDF2(PRF, Password, Salt, c, dkLen)

DK is generated derived key, PRF is a pseurandom function of two parameters, c is the number of iterations, and dkLen is the output length. 

The Wireless network in your home is probably setup with WPA2, which looks a lot like this:

DK = PBKDF2(HMAC−SHA1, your password, your ssid, 4096, 256)

It makes finding the password much more difficult, but not impossible. This brings me to my next point: You probably should change your master password. I wouldn't worry too much about your password vault getting looked at by the wrong people, but I'd rather play it safe than be sorry by changing your master password. It will make your current PBKDF2 unreadable by non-privy eyes.

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