About rijndael-cbc@lysator.liu.se

Hello,

You're probably looking at this page because you've found "rijndael-cbc@lysator.liu.se in your ssh log files, when looking at failed login attempts. As an example, you may have found lines like this:
no matching cipher found. Their offer: aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,arcfour128,arcfour,3des-cbc,none [preauth]
It is not an email address, despite looking like one to you. Nor is it a user/member of the Lysator Academic Computer Society. It is instead an alias for the cipher better known as AES (Advanced Encryption Standard), as implemented by one of our members before it was named aes256-cbc by the IETF. It is named as customary for such ciphersuites, i.e. a name and a domain connected by an @ sign, and was left in by many ssh protocol implementations after this for backwards compatibility. It can be worth mentioning that it has also been deprecated in OpenSSH since 2014 with the release of OpenSSH 6.7.

In short, trying to pin any "hacking attempts" on us over this would be barking up the wrong tree. You could probably find a source IP somewhere else in your log files, but there's probably not much use going after them either, to be honest.

Best regards
The Lysator Academic Computer Society