DNSSEC Key Rollovers Explained

In an earlier post I explained the idea of DNSSEC how to generate keys and sign your DNS zone. In this post I will walk you through the rollover methods as described in RFC 6781. You should understand the rollover process so that you can securely run your zone. This way you can  replace the key in a secure manner when necessary, without service interruptions.

In the earlier post I explained that there are two sets of keys for most DNSSEC signed zones, a Key Signing Key (KSK) and a Zone Signing Key (ZSK). The ZSK is used most often, and should be replaced about yearly, and is also the easiest to replace. Once that process is explained, it is easier to understand how to rollover a KSK also. Continue reading

Going down an elliptically curved rabbit hole

Yesterday I posted a guide to securing your nginx server with some good SSL settings. As I mentioned in that post, I am eager to get rid of RSA entirely, because it is going to be broken at some point in the not so distant future. So I spent part of the day researching the possibility of using Elliptic Curve Cryptography for my site, below are some of my findings.

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Securing your site with nginx

This week in the Netherlands the news hit again that some secure websites where vulnerable to a downgrade attack. This attack is not new, but for the average user it is hard to detect. You have to be careful that you see the lock when you are entering your credentials.

Fortunately, most new web servers and browsers have a setting for it, called HTTPs Strict Transport Security (HSTS). With that feature enabled, if your browser has ever contacted a website over a secure link (HTTPS), then it will not allow a downgrade to plain HTTP for that host. This of course means that you are more secure, at least as long as you watch out for certificate warnings. I use the nginx webserver, and use some other things for security, which I’ll share with you below. The SSLLabs test will give this configuration an A+ currently.

Edit 26/3: @okoeroo gave me a better list of ciphers which scores even higher with SSLabs:

    ssl_ciphers  ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-SHA256:ECDHE-RSA-AES256-SHA:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-SHA:DHE-RSA-CAMELLIA256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES256-SHA:DHE-RSA-AES256-SHA:DHE-RSA-CAMELLIA256-SHA:ECDH-RSA-AES256-SHA:TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:TLS_DHE_RSA_WITH_AES_128_CBC_SHA:CAMELLIA256-SHA:AES256-SHA;

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WhatsApp Alternatives part 2 – Secure Communication

This is an addition to my other post about WhatsApp alternatives. There are others that provide more than just messaging. Below is my personal impression about these. Continue reading

WhatsApp alternatives

Update: Threema support responded: traffic-data is deleted when the message is delivered, or after two weeks, whichever is earlier.

The popular WhatsApp messaging service has been bought by Facebook last week. It is reassuring to see that many people are worried about this. It means Facebook can collect and combine even more data about you than they already do. They now have the posts that you share with all your friends, but now they also have the messages that you share with your best friend, or with the small selected groups of friends. The worrying means that people are now looking for alternatives, and below is my personal take on some of the alternatives that I’ve seen. Continue reading