He said during Question Hour in Rajya Sabha that frauds involving net banking and debit/credit cards is a small fraction of the total number of transactions in the country.
"There is no proposal to discourage use of net banking and debit and credit cards. In fact, we must encourage it as such transactions are recorded and leave an audit trail," he said.
He said 97 cases of frauds involving Rs 1.05 crore were reported in 2009 which rose to 155 cases with Rs 3.69 crore fraud amount in 2010.
In the subsequent year, Rs 6.72 crore was involved in 128 cases of fraud net banking/debit/credit card transactions.
This year, 155 cases have been reported till September 30 and the amount involved was Rs 5.7 crore.
"RBI is vigilant in the matter... Banks have been asked to be vigilant," he said, adding each case of fraud will be investigated and fraudsters brought to justice.
Asked about phishing attacks, Chidambaram said if there was any deficiency in the IT Act, he will bring them to notice of the Telecom and IT Minister Kapil Sibal for possible amendments in the Act so as to punish such cyber crimes.
RBI, he said, had in July issued a Master Circular advising banks to set up internal control systems to combat frauds and to take pro-active fraud control and enforcement measures.
Fraudsters develop new techniques to cheat with advancement of technology but "we must be one step ahead of fraudsters," he added.