From this document: https://www.ssllabs.com/downloads/SSL_Server_Rating_Guide.pdf https://www.ssllabs.com/downloads/SSL_Server_Rating_Guide.pd... Keys below 20

From this document: https://www.ssllabs.com/downloads/SSL_Server_Rating_Guide.pdf https://www.ssllabs.com/downloads/SSL_Server_Rating_Guide.pd... Keys below 2048 bits (e.g., 1024) are now considered weak, and the grade capped at B. New grade A+ is introduced for servers with exceptional configurations. At the moment, this grade is awarded to servers with good configuration, no warnings, and HTTP Strict Transport Security support with a max-age of at least 6 months. Therefore A+ means key length>=2048 with other good config (TLS 1.2 and so on) and HSTS max-age>=6 month.