Encryption is supported with partitioned files.
Notice that there is an important complication with archived partitions. Encryption involves creating a random key for each individual physical file. That data encryption key is in turn encrypted with the master key. This is why a single master key can decrypt an entire database and each file is still protected by a unique "private" key. Partitioned files are collections of many physical files. Imagine you archive a set of those files and physically remove them, then change (rotate) your master key as you should over time. If you bring the archived partitions back online at a future time, you can no longer decrypt their contents because the original master key is no longer available.