Many countries, like the US, have laws which regulates cryptography usage or export.
Because east-tec InvisibleSecrets use strong cryptography it is restricted by such laws.
The US Export Restrictions
The trial version of east-tec InvisibleSecrets restricts the key length to 5 characters (only 40-bits). Therefore it is re-exportable from the US. This restriction is only for the encryption process. You can decrypt a message which was encrypted with the full version (and a key larger than 5 characters).
The full version has no key-length restrictions. It cannot be exported from US or Canada but it can be legally imported (because East-Tec is not an US vendor).