On Jan 13, 2009, at 9:29 PM, Ulric Auger wrote:

> I started to use SEE and I was surprise to notice that the file size  
> of my
> encrypted database is the same has the un-encrypted database, how  
> come?
>
> It seems too good to be true, I was sure that the encrypted database  
> would
> have been bigger.

AES128 uses 12 bytes per database page for the encryption nonce - so  
that is only about a 1% overhead.  AES256 uses 28 bytes per database  
page.  So an encrypted database might be 1% or 2% larger on average.   
But all database files round off to the page size, so in your case,  
they are probably rounding off to the same size.  If you keep  
searching, you might eventually find a database that is one page  
larger after encryption.

>
>
>
>
> Also, I timed some query (insert and select) and couldn't see  
> noticeable
> speed difference.
>
> Again this seems too good to be true.
>

You probably have a fast CPU relative to the speed of your disk.   
SQLite is really spending all its time doing disk I/O.  The extra  
overhead for AES doesn't make that much difference.

Your mileage may vary on other machines with different CPU-speed to  
Disk-speed ratios.

>
>
>
> Anybody having these great performances with SEE?
>
>
>
> My test where done with SQLite 3.6.8 with AES128 and AES256.
>
> Using a hex editor the encrypted database was definitely scrambled.
>
>
>
> Thanks
>
>
>
> Ulric
>
>
>
> _______________________________________________
> sqlite-users mailing list
> sqlite-users@sqlite.org
> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users

D. Richard Hipp
d...@hwaci.com



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