Ldunbar wrote: If Adobe is going to bill rot-13 as a secure encryption, they have got to take measures to ensure that it is strong enough to withstand cracking without the DMCA standing in front of it. Frankly, I find it ironic that adobe's lawyers, not their programmers, are the only ones capable of protecting the content from being cracked.
The issue here is not a technical one; use of rot-13 is as strong as use of Rijndael/AES here. In fact, from an engineering perspective, rot-13 is superior: Its faster, takes less memory, is less error prone, and equally secure. This is because the key to decrypt the content needs to be locally available, and when the key is locally available, I can reverse engineer and get at it. This is of course, the use of a technical system to fix a social problem, and those tend to fail. We'd all be better off if Adobe put a big sign saying "Do not copy!" in some human and machine readable form. Thats superior to rot-13 and AES, and is clearly a lawyers-only way of protecting your content.