For example, when we need to restart a server. Next the user is asked for the size of the CA key in bits. This is the size of N in RSA, the product of the two large prime numbers. This affects the security of the Certification Authority. A choice of 512 bits is not considered safe while one of 1024 bits is considered relatively safe.
Key generation takes place once in the lifetime of the key.
Other operations, like the signing and verification of digital signatures, take place more frequently and remain to be benchmarked. This takes several seconds. The user should wait for it to complete. This is the procedure described in the section called Generate a certificate request in Chapter 4 . This option exports the CA certificate request generated above.