Setting a CipherKey

How would we go about setting our own CipherKey?

Currently we using a cipherKey that has been setup by helical when we got the application.
Can you guide us on how we can set our own encryption Key.

In order to change the cipherkey go to the Location: \apache-tomcat-7\webapps\hi\WEB-INF\classes
In customAuthetication.properties change the value of cipherKey as shown in the following screenshot.
IMG_27122017_135716_0
After making the changes save the file.
Note: The length of cipher key should be 16 and the cipher key used in the properties files should be similar to that of the key used while encrypting the token.