Target CIO Beth Jacob has resigned following a data breach at the retailer that may have affected as many as 110 million US residents.

Jacob's resignation was reported by the Associated Press today. She has been CIO at Target since 2008, and is former director of guest contact centres and vice president of guest operations at Target. She earned a bachelor's degree in retail merchandising from the University of Minnesota in 1984 and an MBA in 1989.

In mid-December, Target reported a data breach that compromised 40 million credit and debit card accounts from late November to mid-December. ID thieves compromised the retailer's point-of-sale system, according to reports.

In January, the department store reported a theft of additional personal information from up to 70 million customers.

Target didn't immediately respond to a request for comments on Jacob's resignation.

Target is overhauling its information security practices, Gregg Steinhafel, the company's chairman, president and CEO, said in a statement. Target is searching for an interim CIO to help guide the company "through this transformation," he said.

In addition, Target is elevating its CISO role and hiring for that position and for a chief compliance offer, he added. The company has hired Promontory Financial Group "to help us evaluate our technology, structure, processes and talent as a part of this transformation," he said.

Former Barclays CIO Anthony Watson, who will be joining Nike as their Global CIO in April, wrote a guest article on CIO about the Target data breach and the importance of cyber security in the financial services sector at the start of this year.