NEW DELHI: The records of up to 500 million customers of the world’s biggest hotel chain Marriott International have been compromised in a data breach.The guest reservation database of its Starwood division has been compromised by an unauthorised party, the hotel chain said in a statement on Friday.Starwood hotel brands operating in India include Le Meridien, Westin, W, Four Points by Sheraton, Aloft, and Sheraton.Marriott did not provide details on the impact of the breach on its Indian customers, but industry executives said it would be significant. “The fact that this goes back to 2014 makes this a very big data breach,” an industry executive said on condition of anonymity. “Starwood has a big presence in India and has been a big brand even prior to the Marriott-Starwood deal. They have had a significant presence in India through a partnership with ITC hotels for the Luxury Collection and brands like Westin, and Four Points by Sheraton,” the executive said.In a global press statement, Marriott said it learnt during an investigation that there had been unauthorised access to the Starwood network since 2014.The company recently discovered that an unauthorised party had copied and encrypted information, and took steps towards removing it.“On November 19, 2018, Marriott was able to decrypt the information and determined that the contents were from the Starwood guest reservation database,” the company said in a statement.For approximately 327 million guests out of the 500 million customers, the information includes some combination of name, mailing address, phone number, email address, passport number, Starwood Preferred Guest (“SPG”) account information, date of birth, gender, arrival and departure information, reservation date, and communication preferences, Marriott said. For some, the information also includes payment card numbers and payment card expiration dates.“There are two components needed to decrypt the payment card numbers, and at this point, Marriott has not been able to rule out the possibility that both were taken,” the company said.