Crypto 101 started as a presentation at PyCon 2013. It tries to go through all of the major dramatis personae of cryptography to make TLS work in 45 minutes. This book is the natural extension of that, with an extensive focus on breaking cryptography.
Internet censorship is bad – especially when it is abused to censor media reports about potentially corrupt government officials. Luckily a lot of incompetent people try to implement censorship via DNS.
Censorship via DNS is a method which is pretty easy to bypass and some people have responded to this this:
A vulnerability was discovered that affects the certificate verification functions of all gnutls versions. A specially crafted certificate could bypass certificate validation checks. The vulnerability was discovered during an audit of GnuTLS for Red Hat.