How are the authentication keys stored, and accessed? Does Litera have access to them?
The AWS authentication keys are accessed and stored in the AWS instance configuration panel. Litera employees do not have access to the keys and AWS key configuration if the authentication is set up to not allow vendor access. The Protect add-on can have authentication given to CAM with reduced permissions if this setup is desired. Other licensing tier tenants will allow Litera to have access to keys.
Is Business Continuity implemented as a full sync of all changes or as a backup of the DMS library?
Yes to both, it syncs changes moving forward in time as well as brings in all document versions that already exist (how far you go back is configurable by the number of days since last modified)