determining which SSL ciphers to use in server block

July 27, 2016 432 views
Let's Encrypt Security Nginx Ubuntu

I am following along to the tutorial how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-14-04 and on Step 3 the author suggests I allow only "the most secure SSL protocols and ciphers" and then provides ciphers within some code to add to my server block.

I was wondering if anyone can explain how the author came to decide on these ciphers specifically? After searching I found lots of other ciphers such as the ones provided on mozilla.org or a recommended suite from https://raymii.org.

Could I use these ciphers instead? Should I?

Thanks for reading. As you can see I am trying to understand ciphers.

2 Answers

https://cipherli.st/ maintains a decent list. Also you can use https://www.ssllabs.com/ssltest/ to determine which ciphers you wish to use.

The most recent cipher suites use RSA, ECDH, or ECDSA for authentication, ECDHE for key exchange, AES for encryption, and GCM for integrity, but a large number of older and backward-compatibility cipher suites also exist.

Source - https://securityevaluators.com/knowledge/blog/20150119-protocols/

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