Executives at US retailer Target and Neiman Marcus have apologised before the US Senate Judiciary Committee over recent data security breaches that disclosed the data of millions of customers.
Target executive vice president John Mulligan said: "We know this breach has shaken their confidence in Target, and we are determined to work very hard to earn it back."
"I want to say how deeply sorry we are for the impact this incident has had on our guests - your constituents," Mulligan added.
Neiman Marcus chief information officer, Michael Kingston, claimed that the actual number of accounts hit by the breach was less than the reported figure of 1.1 million accounts.
"We do believe because the malware was only operating at certain times that the number is less than that," Kingston told Reuters.
Kingston also said that there was no sign that the data breach had posted transactions on the company's website or at its restaurants, while its PINs were also not compromised.
Committee Chairman Patrick Leahy said that US consumers deserved to know when their private information had been compromised and what businesses were doing in response to cyberattacks.
"Public confidence is crucial to our economy," Leahy said.
"If consumers lose faith in business' ability to protect their personal information, our economic recovery will falter."
In a move to avoid similar data breaches, Target revealed plans to invest $100m to adopt chip-enabled smart cards to prevent cyber theft.
The new chip-enabled smartcards, claimed to be safer compared to the commonly used magnetic stripes, incorporate minute microprocessors that encrypt personal data shared with sales terminals.