The concern for security may be considered as two issues.
The first is the issue of theft and copyright. If a hyperbook is to be distributed, some form of encryption may be desirable to prevent text from being used without authorization. Encryption and compression go hand in hand. A file that has been encoded in order to decrease disk space requirements will also be effectively encrypted.
The second issue concerns LAN security. If a hypertext system exists in a multi-user environment, restrictions may have to be placed on access rights.