Secret! and security 

We don't believe in Security by Obscurity.  An encryption tool which
does not name the algorithm used can not really be trusted. 

Secret! uses a well-known standard encryption algorithm, the strong IDEA
(International Data Encryption Algorithm) to protect your data. IDEA
is a symmetric 128 bit block cipher has not been broken so far.  It is
discussed in the literature (e.g. in Bruce Schneier's excellent book
Applied cryptography) and believed to be secure. The encryption algorithm
is identical to the one used in Secret! 2.0, the source code of which
has been send to hundreds of interested users. This makes the chance of
implementation flaws very small.  

The 16 character password may consist of the up to 44 keys of the
on-screen keyboard or, if you use graffiti to enter the password, of up
to 93 graffiti strokes.  While this gives an effective key length of
16 * ld 93 = 105  bit and does not totally fill the 128 bit IDEA key
space it is still very strong and gives brute-force attacks a hard job:
There are 93**16 = 3 * 10**31 password possibilities. If you were using
all the computers in the Internet (approximately 40 million) and each
one were to try one password per nanosecond (1 billionth of a second),
you'd still  need 8 * 10**14 seconds or 25 million years to find the
one and only correct password to decrypt the data stored in  Secret!  

Much care has been taken to ensure no copies of your data are lurking
around unprotected. Dynamic memory is overwritten with zeros and the
entered password is erased as soon as it is no longer needed. The database
that is backed up during hotsync contains at any time only the encrypted
version of the data. 

Secret! has a unique auto-close feature that closes the data screen and
encrypts all data after a predefined time or as soon as you switch to
the Launcher or power off your PalmPilot. The data is even encrypted
before  the device automatically turns itself off to save batteries. 

As LinkeSoft is a German based company, we are not subject to US export
restrictions and can such deliver true and untampered  encryption power. 

(C) LinkeSoft  17-Apr-1999
