Privacy is one of the core principles of the Verisart system and you control what information you choose to share (and with whom) at all times.
Although certificates are recorded on the blockchain, they are done so anonymously. So nobody can discover the owner of a specific work, unless the owner chooses to make that information public. It also prevents anyone who is not an owner of an artwork from discovering the personal details of the previous owner or owners.
The current owner can share that information with a specific party when they choose (such as in the case of a pending sale).