Take timestamp from receiving message and check if it's really fresh or it's an old message (attempt to perform a replay attack)

Add salt to the user object, and stores the 👍

hash("password" + "salt")

where "salt" is a random string.

The deploy of the rest application cannot be done, probably a problem with tomcat deploy

We can't make the deploy of MobileCashServer at Heroku.

Receive a payment object and verify integrity of the message.

• Hash everything and compare with received hash

Change payment message to a json object like this:
{ username : username,
password : password,
product : product
timestamp : timestamp,
hash : hash(rest of the message)
}