All About CSRs and RSAs

If you are transmitting sensitive information like credit card numbers or personal information, you need to secure it with SSL encryption. It is possible for every piece of data to be seen by others unless it is secured by an SSL certificate.

The CSR and RSA key are two components involved in the generation of an SSL certificate. These are provided as blocks of encrypted text and can be confused with one another; however, they are quite different and fill very different roles.

What is a CSR?

A Certificate Signing Request, or CSR, is a block of encrypted text which contains information that will be included in the SSL certificate itself. This includes data such as the organization name, domain name, locality and country. It also includes the public keys for the SSL certificate.

The CSR is generated by the server on which the SSL certificate will be installed, and is then used by the SSL certificate provider to create the SSL certificate itself.

If you are renewing your certificate or if your certificate is expired, then you will need to request a new CSR.

What is an RSA Key?

An RSA key is the private encryption key that will be used to protect sensitive information. As the name implies, an encryption key is used to encode and decode information securely.

Currently, we use a 2048-bit RSA key.

The RSA key is generated by the server which the SSL certificate will be installed upon. You will receive the RSA Key when the CSR Request is submitted.

How Do I Get These?

The CSR will be sent by you to your third-party SSL provider and used to create the SSL certificate itself.

The RSA Key is then returned to us (along with the actual certificate itself) when requesting installation of your third-party SSL certificate.

See also Generate SSH Keys and Connect to Your Account via PuTTY (Windows), Secure Sockets Layer (SSL) Overview, Install an SSL Certificate, Transfer Current SSL to New Account