Saving encrypted customProperties outside the app?

Mark Brownell gizmotron at earthlink.net
Mon Sep 29 22:14:00 EDT 2003


On Monday, September 29, 2003, at 08:16  AM, Richard Gaskin wrote:

>> Mark Brownell wrote:
>> There are export restriction laws in place by different countries 
>> that need to be followed when implementing it. This becomes the 
>> responsibility and liability of the developer using it in their apps.
>
> Wouldn't the disclaimer included with the original Blowfish algorithm
> suffice?

Richard,

If you mean from here: http://www.schneier.com/paper-blowfish-fse.html 
it might if I didn't need to explain the first part where the 
rev_blowfish app tries to restrict the encryption key level to 128 bit. 
It checks for proper key formation and usage. I built this as a 
demonstration of implementing blowfish. It is not really part of the 
Blowfish algorithm that comes up after key checking part. Blowfish 
works from 32 bit to 448 bit encryption levels in 32 bit level steps. 
The original disclaimer does not reflect the changes in security that 
have come along since 1993; either that or I forgot what it said. I'm 
not going to look it up.


> For speed it would seem optimal to have it implemented in an external, 
> or in the engine itself.   The usability issues could be addressed 
> along with that. Have you talked with Tuv about the possibility?
> -- 
>  Richard Gaskin

No. I've talked with a few others at Rev about it though. If it were 
put into the engine then it would be limited to 128 and 64 bit formats 
because of export restrictions. That could put limitations on Rev 
distribution.

If you add Blowfish into your own standalone apps this makes you, the 
developer, the person that needs to distribute the app properly under 
export laws. I have copyrighted the rev_blowfish.rev app so that I can 
claim restrictions on the actual rev_Blowfish.rev app. The source code 
inside rev_Blowfish.rev is free to use at your own risk if used 
responsibly just like it was back in 1993 by Bruce Schneier I learned 
from other open source examples in C, Visual Basic, and Lingo. This is 
just an example of it in Transcript.

Mark






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