MANILA - Voting machines to be used in the upcoming 2019 elections were "enhanced" to make voting "more efficient," the Commission on Elections (Comelec) said Thursday as the agency prepared for the May midterm polls.

There will be no changes on how the machines will be used as most of the upgrades were made on the back end, Comelec spokesperson James Jimenez told reporters.

"Ang enhancements niya ay (Its enhancements are) mostly in the back-end, in how the system operates and how it is more efficient now than before," he said.

(Most of the enhancements are in the back end, in how the system operates and how it is more efficient now than before.)

"Increasing the encryption strength, changing the architecture of the saving so that when you save you can save it simultaneously instead of saving it one after the other doon sa kaniyang (in its) back up cards," he said.

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Jimenez did not say if security features of the voting machines were also enhanced.

Over the years, several candidates and tech experts have alleged that the Precinct Count Optical Scan (PCOS) machines could be used to rig election results.

The Comelec had denied such allegations and purchased at least 97,000 vote counting machines from contractor Smartmatic last year.

• READ: How PCOS machines can be used to cheat in elections
• Comelec to purchase vote-counting machines used in 2016