How Direct Recording Electronic (DRE) Voting Machines Work

A Direct Recording Electronic voting machine, or DRE, works by loading a voter’s ballot onto a screen, recording each selection directly into computer memory, and storing the totals for transfer to a central tabulator after polls close. There is no paper ballot marked by hand. The voter is authenticated by a poll worker, given a smart card or access code, and makes choices by touchscreen or push-button; the machine writes those choices to internal flash memory and to a removable encrypted memory card, and on some models also prints a paper record the voter can verify through a window. DREs became widespread in the United States after the Help America Vote Act of 2002, though only about 3.9 percent of registered voters now live in jurisdictions that use them as the primary system for all voters.¹

What the Machine Looks Like at the Polling Place

A DRE is a self-contained unit, usually inside a privacy booth or on a dedicated stand. Inside the housing is a small computer that drives the ballot display, records votes, and coordinates the attached devices. The voter sees a touchscreen or a console with push-buttons next to each ballot option. The case is high-impact plastic or metal built to shield the circuitry from accidental damage or tampering.

Most units have a card reader or token slot that a poll worker uses to start a session, plus connectivity ports on the back or side for loading ballot files before the election and pulling results afterward. Those ports are sealed during voting hours. Federal guidelines require DRE machines to operate on battery backup for at least two hours if the main power fails, keeping voting available and protecting stored data during an outage.² A DRE without power is unusable, unlike a paper-ballot system where voters can still mark ballots by hand.

Casting a Ballot Step by Step

Once a poll worker verifies eligibility, the voter is handed an encoded smart card or given an access code. Inserting the card or entering the code loads the correct precinct ballot, showing only the races and measures that voter is eligible to decide. The voter taps or presses to select candidates and ballot measures, and each choice highlights on screen to confirm it registered.

The interface pages through local, state, and federal contests. If a voter tries to pick more than one candidate for a single office, federal law requires the machine to flag the error and explain the consequences before the ballot is recorded.³ For write-ins, the voter picks a “write-in” option, an on-screen keyboard appears, and the typed name becomes the recorded choice for that race.

After the last race, a summary screen lists every choice. Federal law requires this review step so voters can catch and fix mistakes privately before finalizing anything.⁴ Pressing “cast ballot” locks in the selections, clears the screen, and resets the machine for the next voter.

How Accessibility Voting Works on the Same Machine

Federal law requires at least one voting system at every polling place in a federal election to be fully accessible to voters with disabilities, giving them the same privacy and independence as any other voter.⁵ DREs are often used in that role because the electronic interface can adapt to different needs.

For voters who are blind or have low vision, the machine plays an audio ballot through headphones, narrating every race and option. A handheld pad with Braille labels and distinctly shaped buttons lets the voter navigate and select by touch alone. The display can also switch to larger fonts or high-contrast colors for voters with partial vision. Standard ports accept sip-and-puff controllers and other adaptive switches for voters with limited mobility.³

Where the Vote Goes After You Press Cast

When a ballot is cast, the machine writes the selection data to at least two places: internal flash memory and a removable encrypted memory card. That redundancy means a failure in one storage medium does not destroy the vote record. The Voluntary Voting System Guidelines (VVSG 2.0) require all cryptographic functions in voting systems to use modules validated under the Federal Information Processing Standard (FIPS 140), with encryption strength of at least 112 bits.⁶

The Air Gap

DRE machines are not connected to the internet or any external network during operation. The EAC defines this “air gap” as using single-use memory devices to move results from the DRE to the election management system, and from there to any public-facing website.⁷ Removable media should come from a trusted source and, where possible, be write-once or read-only so files cannot be altered after creation. A USB drive that has been plugged into an internet-connected device should not be reused in the voting system without being verified clean of malware.

Closing Polls and Tabulation

At the end of voting, poll workers run a “close polls” procedure that freezes the data and blocks any further entries. Each machine prints a results tape showing totals for that unit. The sealed memory cards are physically transported to a central tabulation facility, where counting systems combine data from every unit to produce unofficial results. Chain-of-custody procedures govern each step of that transfer. Deliberately interfering with the tabulation process in a federal election is a crime punishable by up to five years in prison.⁸

Paper Trail Models vs. Paperless

Some DRE models include a Voter-Verified Paper Audit Trail, or VVPAT. A small printer sits behind a clear viewing window on the machine. After the voter makes electronic selections, the printer produces a paper record of those choices. The voter reads the printout through the window to confirm it matches their intent, but cannot touch or remove the paper. If the printout is wrong, the voter can cancel and re-enter selections before casting.

Printed records stay inside a sealed canister within the machine, creating a physical trail that exists independently of the digital data. Federal law requires voting systems to produce a permanent paper record, and that record is available as an official record for any recount.³ Officials can cross-reference the electronic tally against the paper trail when discrepancies come up. DRE models without a VVPAT produce no independent physical record, which is the central point of controversy around these machines.

Why Security Experts Focus on the Paper Record

DREs have drawn sustained criticism from computer security researchers since their widespread deployment. Everything between the voter touching the screen and the final tally happens inside the computer, invisible to human observation. If malicious software altered votes, neither the voter nor an observer would necessarily catch it. Early independent reviews of one major vendor’s DRE software identified serious flaws that could be exploited by voters, election workers, or outside attackers, and a follow-up review of the same system as deployed in Maryland rated it at high risk of compromise, listing 14 specific vulnerabilities, most involving procedures and personnel rather than hardware alone.

Several factors compound the risk. DRE software is moderately complex, and complex software is hard to audit for unauthorized modifications. Manufacturers have historically treated source code as proprietary, limiting independent review. Malicious code can also be written to activate only under specific conditions, such as a particular date or vote count. The most effective mitigation has been the VVPAT, which creates an independent paper record a voter can verify. Machines without any paper trail offer no way to audit the electronic count against a physical record.

Pre-Election Logic and Accuracy Testing

Before every election, local officials run logic and accuracy (L&A) testing on each DRE unit to confirm it records and counts votes correctly. Workers cast a known pattern of test votes, including deliberate overvotes, undervotes, and blank ballots, then compare the machine’s tally against the expected results. Teams also verify that ballot activation devices produce the correct ballot for each precinct, that the audio ballot works, and that all accessibility devices function.⁹

EAC guidelines call for testing in bipartisan pairs where state law requires it. Any discrepancy between expected and actual results must be investigated and documented. Equipment with unexplained errors is flagged for replacement or maintenance. After testing, workers apply numbered security seals and record the seal numbers, and the testing session is formally closed in the system so test votes do not carry over into the actual election tally. Many states require public notice of L&A testing and allow media, candidates, and party representatives to observe.⁹

Where DREs Are Still Used

DREs are far less common now than at their peak in the mid-2000s. As of 2026, about 3.9 percent of registered voters live in jurisdictions using DREs as the primary voting system, with roughly 2.6 percent using DREs equipped with a paper trail and 1.3 percent still using paperless models.¹ Most U.S. voters now use hand-marked paper ballots counted by optical scanners, or ballot-marking devices that produce a paper record.

Several states that once relied on DREs have moved fully to paper-based systems, including Georgia, Pennsylvania, Virginia, and South Carolina. A handful of states still have paperless DREs in some counties, with Texas holding the largest remaining concentration. The shift reflects both the security concerns above and the growing emphasis on post-election audits, which need a paper record to be meaningful. Jurisdictions still using DREs face the practical hurdle that replacing voting equipment costs thousands of dollars per unit, and many local governments have struggled to fund the switch.

1
Verified Voting. The Verifier – Voting Equipment – November 2026
2
U.S. Election Assistance Commission. EAC Decision on Request for Interpretation 2023-05 – Power Outages, Sags, and Swells
3
Office of the Law Revision Counsel. 52 USC 21081 – Voting Systems Standards
4
U.S. Government Publishing Office. Help America Vote Act of 2002 – Section 301 Voting Systems Standards
5
U.S. Election Assistance Commission. EAC Advisory 2005-004 – How to Determine if a Voting System Is Compliant with Section 301(a)
6
U.S. Election Assistance Commission. Voluntary Voting System Guidelines Version 2.0
7
U.S. Election Assistance Commission. Best Practices for Election Technology
8
Office of the Law Revision Counsel. 52 USC 20511 – Criminal Penalties
9
U.S. Election Assistance Commission. Logic and Accuracy Testing EAC Quick Start Guide