Darren and I talked about the areas of overlap between lofi encryption and lofi compression. Here's a summary of what we talked about -
Compressed lofi images are read-only so it makes sense to allow either compression or encryption on an image but not both at the same time. So, lofi compression should be able to spot an encrypted image and prevent compression. Likewise, lofi encryption should be able to spot a compressed image and prevent encryption. This obviates the need for on-disk metadata to be stored by lofi encryption. In other words, there is a dependancy between PSARC/2007/001 and this case. The two project teams will work together to make sure that encrypted images can't be compressed and vice versa. Also, I need to make it clear in the documentation that compressed lofi images can be read-only and not read/write. Alok
