[Harry says] It's hint time for 8B

So many hints! I seem to have spent the last few days just trying to decide which hints to block, and which to publish, but now it is time to be a little (only a little) more generous. You really do need to crack 8A to do 8B. First because Trinity tells you something crucial about the encryption method in 8B and second because even when you figure out what she is talking about, and even after you work out exactly how it was done, you will still need 8A from time to time. Maybe more later, but not today! Harry