Maryland election officials plan to use an expanded wireless network during the 2020 elections, prompted by a new law allowing people to register to vote on Election Day. But at least one lawmaker and a local elections board are questioning whether the new system will be worth the cost and will be safe from hackers.

A cellular network will transmit new registrations from local polling places to state elections officials throughout Election Day, allowing officials to update voter lists that help meet objectives including that no one vote twice.

“It’s creating a path, a road, for the voter check-in data to go from the poll books to our server here,” said Nikki Charlson, the deputy administrator at the Maryland State Board of Elections. She said the step is necessary to enable “local officials to do their research to prepare to count the votes.”

Charlson said the only information the network will carry is who is registered and has voted, not how any person voted. The same type of network is used by law enforcement and public safety agencies, she said.

“It’s using cellular data, but it’s a secure and closed network,” she said. “No one can find it, and the data’s encrypted, and the network is encrypted.”

The state already uses a similar, though smaller-scale, network to upload new registrations during early-voting periods. “So this was taking something we did in early voting and bringing it to Election Day,” Charlson said.

But state Sen. Cheryl C. Kagan (D-Montgomery) said the networking equipment, which will cost counties hundreds of thousands of dollars, is not needed and “makes us more vulnerable to hacks and attacks.”

Kagan said she plans to sponsor emergency legislation in January to ease deadlines under which local officials must tally votes. Such a change, she said, should eliminate any justification for “this risk and cost . . . so that we put the brakes on this terrible idea.”

The plan for a wireless network drew concerns from across Maryland after state officials broached it during a conference call with local elections directors in February, while lawmakers were still considering the same-day voter registration law.

After the call, David Garreis, the president of the Maryland Association of Election Officials, raised concerns including potential connectivity problems and whether poll workers could be trained on the network fast enough.

“Given that the 2020 elections will be particularly high profile, and may involve historic voter turnout, the [local boards of election] do not want to risk implementing a process or system that does not have [the state board’s] full confidence of success,” Garreis wrote in a March letter to Linda Lamone, the administrator of the State Board of Elections.

Charlson said the state has worked with local boards since then to alleviate concerns.

“We’ve moved a long way since March, and they are comfortable with the solution that we’ve chosen, and they’ve been testing it,” Charlson said.

One change to the original plan is that only the state’s six largest voting jurisdictions will implement the system next year. Charlson said it is easier for smaller counties to transmit their poll book data all at once by the deadlines set for election night, so updating registration data throughout Election Day is not as critical for them.

Garreis, who is also deputy director of Anne Arundel County Board of Elections, did not respond to messages seeking comment. But officials in at least two other counties confirmed they are now generally comfortable with the plan.

“It’s tested just fine so far,” said Guy Mickley, Howard County’s elections director. “Howard County’s on board and will be networking the polling places for the 2020 elections.”

Alisha Alexander, the elections administrator for Prince George’s County, said she is working to make sure poll workers there will be ready for the technical ­changes.

“Any time you’re implementing something new, there is some apprehension about the rollout,” she said. “But at this point, we will move forward with this network connection as mandated by the state.”

Montgomery County’s Board of Elections, however, has asked state officials to reconsider. In October, the board’s chairman, James Shalleck, cited security concerns and an estimated $365,000 cost to the county.

The board was “not persuaded at this time that there is a sufficient justification for only a few counties to conduct this experiment for the State Board,” Shalleck wrote in a letter.

Lamone, the state elections administrator, responded that she felt the costs were justified and the security risks minimal.

“Securing election networks is of the utmost importance, and I am confident that the proposed election day network will be as secure and reliable as possible,” she wrote in a November letter to Shalleck.

Shalleck said he wishes state officials had been more open during the decision-making process and remains concerned about whether they’ve considered enough expert advice to head off potential risks.

“We’ve been told not to worry about security issues,” he said. “But I’m still worried.”