Freeze has no encryption or compression features built-in, so you are responsible to prepare the data as you want it to be stored on Glacier before you upload it.
I don't like built-in encryption features in file transfer or backup apps too much, because they are often proprietary and that may make it hard to switch to another client.
As a workflow example, I personally encrypt my archives with gnupg and store them on external hard drives and additionally upload them to Glacier for disaster recovery.
Another possible thought for the roadmap would be some sort of pluggable architecture for encryption. Let third-parties develop open encryption plugins that this runs inside prior to uploading.
All data in Glacier is encrypted. Here's the FAQ entry:
> Amazon Glacier handles key management and key protection for you. Amazon Glacier uses one of the strongest block ciphers available, 256-bit Advanced Encryption Standard (AES-256). 256-bit is the largest key size defined for AES. Customers wishing to manage their own keys can encrypt data prior to uploading it.
