In context of Public Key Infrastructure ? By LDAP i mean publicly available public keys exposed by an LDAP server that you can query using the LDAP protocol ? CRL stands for certificate revocation list, in other words it contains certificates not to be trusted. Do these two protocols depend on the same database of public key certificates ? I have a CA here, that announced it would not continue updating the CRL, but their responses to LDAP queries seem up to date.
LDAP is a small light-weight protocol specified by RFC4511. Nowadays the term LDAP is used to refer to the directory information tree (DIT) in addition to the protocol itself
A certificate revocation list (CRL) is a list of certificate serial numbers that have been revoked by an issuing authority or validation authority and therefore cannot be used reliably by clients
LDAP is often used as a data store for PKI information such as public keys, private keys, and certificates and in fact excels at this task