photo by: Associated Press

Ruth Meier, from Silver Lake, Kan., votes at the Prairie Home Cemetery building, Tuesday, Nov. 4, 2014, in Topeka, Kan. (AP Photo/Charlie Riedel)

Topeka ? The chief election officer in Kansas Secretary of State Kris Kobach’s office said Tuesday that a multistate voter registration database that Kansas manages is being thoroughly reviewed for security concerns, but it is unknown whether Kansas will have to foot the bill to upgrade the system.

“I legitimately do not know the answer to that yet,” Bryan Caskey said during a phone interview Tuesday. “We’re still evaluating all options, and one of the options is cost.”

The Kansas secretary of state’s office manages a database known as the Interstate Voter Registration Crosscheck Program, which contains voter registration information for millions of voters in more than 25 states. In some cases, those records include the last four digits of the voter’s Social Security number.

The review began after Pro Publica, a nonprofit investigative journalism organization, published a story in October detailing how easily the system could be hacked.

Crosscheck is a project that began in 2005 when Republican Ron Thornburgh was secretary of state. Originally, it included voter registration data from only four states — Kansas, Missouri, Iowa and Nebraska.

The purpose, Caskey said, was to clean up voter rolls when voters moved across a state line and re-registered in their new state, without asking that their old registration be deleted.

Since Kobach took office in 2011, the program has expanded greatly to include more than half the states. And since becoming vice chair of President Donald Trump’s Advisory Commission on Election Integrity earlier this year, he has asked all 50 states to submit their voter registration information.

According to Caskey, as the system is now configured, states that take part in the Crosscheck system upload their data to a secure “file transfer protocol,” or FTP server, which is physically housed in Arkansas. Kansas then accesses the data from that server and stores it on the secretary of state’s office’s own system.

According to the Pro Publica article, a progressive-leaning group called Indivisible Chicago obtained public records from Illinois and Florida that showed that the files are hosted on a server that is not secure, and that usernames and passwords were frequently shared in emails, making them vulnerable to hackers.

Meanwhile, a number of studies have shown that the Crosscheck system frequently results in “false positives” — identifying potential duplicate registrations in two or more states when, in fact, those registrations are for different people.

The state of Indiana is currently being sued in federal court after passing a law mandating that local election officials purge voters from the rolls immediately whenever Crosscheck identifies a duplicate registration, even though under federal law they are supposed to take steps to contact the voter and verify whether it is a duplicate registration.

Other states, including Idaho and New York, have reportedly considered dropping out of the program.

Douglas County Clerk Jamie Shew, the county’s chief election officer, said he had no direct knowledge about the data security concerns surrounding Crosscheck. But he said his office rarely uses the information it receives from Crosscheck, primarily because it is so inaccurate.

“The first thing is, the majority of Crosscheck, we don’t even look at. If there’s something that has the potential to be a strong match, like a really unique identifier, something that would justify the staff time and expense, it will start the NVRA process,” Shew said, referring to the National Voter Registration Act. “The NVRA process can take up to four years.”

Under that federal law, he said, if there is reason to believe a voter has moved without deleting his or her old registration, the local election officer is required to attempt to contact that voter by mail. If that effort is unsuccessful, the county is only allowed to purge the registration if the voter fails to cast a ballot over two federal election cycles.

“I don’t have legal authority to just remove someone, regardless of what the source of information is,” Shew said. “All the time, we have parents come in and say, ‘My son or daughter no longer lives here, take them off the list.’ I can’t even do it with the parent telling me that.”