Add note about file index compression/encryption

diff --git a/docs/design_ideas.txt b/docs/design_ideas.txt
index d21009b..625ad00 100644 (file)
--- a/docs/design_ideas.txt
+++ b/docs/design_ideas.txt
@@ -73,6 +73,8 @@ Intra2net specific requirement:
   Then we prefix all filenames like above, otherwise not.
   -> full backups contain normal paths.
 
+- the file index should optionally be compressed and/or encrypted, too.
+
 - gzip compression supports appending to existing compressed files (zcat).
 
   The compression for tar archives is usually added on top of the whole