COLUMBIA — Despite last year’s massive breach of sensitive taxpayer data, roughly the same number of South Carolinians this tax season are continuing to file their taxes electronically and to receive their tax refunds directly, according to the state.

Gov. Nikki Haley’s administration called the development a sign that public confidence is returning. State Sen. Vincent Sheheen, Haley’s likely 2014 Democratic gubernatorial challenger and an outspoken critic of her handling of the hacking, said the numbers likely reflect a lack of detailed knowledge of the breach on the part of many taxpayers.

While the state Department of Revenue still is processing returns, about 80 percent of taxpayers had filed their state income tax returns electronically through April 15, consistent with last year, said agency spokeswoman Samantha Cheek.

She said the percentage of filers choosing to have their refunds directly deposited to bank accounts — and providing the state bank account numbers and routing information in the process — stands at 77 percent through April 15.

At that time last year, 75 percent of taxpayers had chosen direct deposit.

The tax collection agency had processed fewer total returns, both electronic and paper, through April 15 compared with 2012.

Complete filing totals for this year will be available in mid-May, because the deadline for electronic returns is May 1 and paper returns are still being processed, Cheek said.

The data breach announced last October saw the theft of 3.3 million bank account numbers, 3.8 million Social Security numbers and information from close to 700,000 businesses.

The breach and its handling by Haley’s administration is expected to be a flash point in the likely campaign between Sheheen and Haley. Sheheen has confirmed a gubernatorial run and is not expected to face a major challenger, while Haley is expected to confirm a re-election bid after the legislative session ends this summer.

Sheheen has cited the breach as of the most visible examples of the failures of state government and the Haley administration to protect taxpayers.

Haley has focused on the steps taken to notify and protect taxpayers through programs such as credit monitoring, along with cybersecurity upgrades to better protect taxpayer data.

That taxpayers thus far have willingly turned their sensitive information over to the state revenue agency in close to the same percentages as before the hacking shows that taxpayers are regaining trust in the department, said Rob Godfrey, a spokesman for Haley.

“Everyone’s confidence in the Department of Revenue was understandably shaken, but sweeping measures have been taken to fix the problem,” he said.

Many lawmakers, including Sheheen, say more needs to be done, such as creating a fund to compensate victims who suffer a loss as a result of the breach.

Godfrey also said this year’s electronic filing and direct deposit numbers show that the leadership provided by Haley’s newly appointed Revenue Department Director Bill Blume is delivering results.

Sheheen sees the filing numbers a different way. He said the percentages are not a surprise at all, given our increasingly electronic society.

Reach Stephen Largen at 864-641-8172 and follow him on Twitter @stephenlargen.