Using custom DH Param in Nginx

Generate DH Param using openssl:

openssl dhparam -out dhparam.pem 2048

In most cases, 2048 is enough and you do not want to use 1024. You may use a key length higher than 2048, such as 4096, but note that there is a computation cost for longer key length.

Next configure nginx to use it for key exchange:

ssl_dhparam /path/to/dhparam.pem;

Finally restart your nginx server.