Has there been any research into compression that's generally safe to use before encryption? E.g., matching only common substrings longer than the key length would (I think?) defeat CRIME at the cost of compression ratio.
I'm working (finishing paper) on an algorithm compatible with deflate/gzip that is safe to use before encryption (i.e. it is guaranteed to not leak random secrets cookies). It's a bit more complex than your suggestion - matching common substrings longer than key length would still be vulnerable as substring boundary may still fall inside secret.
