Fencry relies on the secret cipher key for it's protection of the cipher.
The persons who shall have access to the same secret information, must
know
the secret key that was used during encryption.
There are two important rules :
First be very careful when you exchange the cipher key. Use a secure
way to exchange
the key, or best of all agree on the key before any communication devices
are used.
Mailing the cipher key and then mailing an encrypted message is of course
pointless.
Second do not pick a cipher key using plain text and names but try different
characters
and numbers also. This makes it harder to attack the cipher with brute
force.
Still the key scheduling in Fencry (Fenja 256) creates a lot of CPU time,
this helps against
this type of attacks.
When creating the 32 character cipher picking key from different keys
on the keyboard
will not give you a 256 bits cipher key but less than 200 bits (still
strong).
Try entering some special signs like ¼ (ASCII sign 172), that are
not on the keyboard.
This is done by holding the "Alt" key down while typing on the
numerical keyboard.
any number from 0 to 255 (extended ASCII code).
Using a random process, preferably by using a natural random process or
the built inn
random generator in Fencry, will increase the strength considerably.