1. Consider the following protocol for adding money to a debit card.(i) User inserts debit card into debit card machine.(ii) Debit card machine determines current value of card (in dollars), which is stored in variable x.(iii) User inserts dollars into debit card machine and the value of the inserted dollars is stored invariable y.(iv) User presses enter button on debit card machine.(v) Debit card machine writes value of x + y dollars to debit card and ejects card.Recall the discussion of race conditions. This particular protocol has a race condition.a. What is the race condition in this protocol?b. Describe a possible attack that exploits the race condition.c. How could you change the protocol to eliminate the race condition, or at least make it more difficultto exploit?

The attacker can then intercept and manipulate the data being exchanged between the two parties, allowing them to modify the value of the transaction in transit.For example, the attacker could modify the value of the variable y to be a larger amount than what the user actually inserted, and then modify the value of the variable x to match the new, larger amount. The user would then unknowingly press the enter button, thinking they are adding the amount they inserted, while the debit card machine writes the manipulated value (x + y) to the debit card, resulting in the attacker successfully storing more money to the debit card than the user actually inserted.Race condition is a situation thatoccurs when two or more transactions are performed at the sametime.In the given scenario, the amountthat is available in the card is stored in the variable xand the amount to be added is stored in the variable y.The machine performs x+y and writes the value to user account.The race condition occurs at step (iii). The race condition occurs if some amount is transferredto the account through some online transaction while the userinserting dollars into the machine. The value in the variabley will get updated and the wrong value will get depositedinto the account.For example, user inserts 100 dollars in the machine and this amount will be stored in thevariable y. At the same time, Bob who is the friend of theuser transfers an amount of 50 dollars through online. In thiscase, the amount that is transferred by Bob will get updated andadded to the account of the user. Actually, the money that shouldbe in the account is x+100+50 but, due to the racecondition x+50 will get updated.(c).AnswerThe best way to prevent the racecondition is to lock the current transaction until the update isdone. In the current scenario, the transaction has to be lockedwhile inserting the dollars in to the machine so that the systemdoes not allow any write operation to the account. In databasemanagement systems, there are several locking protocols such asTwo-phase locking protocol, strict two-phase locking protocol ensure the concurrency control.