...It contains an executable file named LGRID_Client_XX.jar.
This is a "double-clickable" jar file, or you can run it from the command line using:
java -jar LGRID_Client_XX.jar
NOTE: To Install JCE Unlimited Strength Jurisdiction Policy Files
If needed, you should install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files.
HcryptoJ (Historical cryptology in Java) is a Java based programming library for implementing and analyzing historical ciphers. HcryptoJ is designed to support research and teaching in historical cryptography and computer science. Licensed under GPL.