Certificates are often considered to be binary blobs that cannot be expressed in human readable form. In this part of my series about what everybody needs to know about certificates (part 1, part 2 and part 3), I will introduce well-known formats for certificates and private keys and how they can be display in clear text to survey the information therein. When different plattforms are involved, conversions between these formats may be necessary to work with the files.

After having introduced the very basic concepts about certificates, we need to dive into the trust issues I raised in the first part of this series. Working with certificates means trusting someone else because a certificate contains a foreign signature combining a public key with identity information. In this part, I will explain why that trust is necessary and how every one of us implicitly places trust in certificates through the operating system.

So far, I have written about averages and correcting your data set. In both articles, I have stressed the importance of recognizing outliers and acting according to generally accepted methods. In this article, I will provide the means to identify outliers and their effect on a data set using histograms.

For those interested, find attached the slides I presented at NRWconf 2011 in Wuppertal. Mind - they are in German!