Canon LBP7780CX User Manual page 720

The generation algorithm when the printer generates a key is RSA.
About the key length
Although using the longer key makes it more difficult to decode data, the processing speed on encryption and decryption
is slower.
Select the key length according to the needs of security for data communication.
5
Specify the effective date and expiration date of the self-sign server certificate.
You can enter date between 1/1/2000 (1 Day 1 Month 2000 Year) and 31/12/2037 (31 Day 12 Month 2037 Year).
6
Specify the country/region name for the self-sign server certificate.
Enter the Internet country code with 2 or less characters.