This is timing attack demo. Requires Apache Maven 3.0.3 to build (http://maven.apache.org/).

To build binaries execute (assuming that mvn is on PATH and you are where pom.xml file is):
$ mvn package

This will execute maven in order to build jar assembly. 
It needs internet connections to download dependencies.
In case of problems with downloads try to re-execute command.
The assembly will be present in directory target/.

Copy the binary assembly to bin/ directory and go there:
$ cp target/keyczar-0.6b-jar-with-dependencies.jar bin/
$ cd bin/

Create signing keys:
$ ./createKey.sh key 0 3
This will create directories key0/ ... key3/ with keys.

Then execute server:
$ ./startServer.sh <lvl> <port> kudofile key
Where <lvl> is level 0 - 3 and <port> is port number as you wish to listen.
This will read key files from directory key<lvl> and write kudofile<lvl>.

To test the server:
$ ./signMessage.sh echo_test key<lvl> message
$ cat message | nc localhost <port>
$ cat kudofile<lvl>
You should see "test".