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The Voting Solutions for All People (VSAP) Ballot Marking Device (BMD) is a voting innovation that improves the voting experience for all voters using technology while retaining a paper ballot as the official, durable and auditable record of the voter’s selections. Throughout the voting experience guidance is provided to the voter promoting verification of selections prior to and after printing the paper ballot. Importantly, the BMD does not record votes electronically and does not retain any information about the voter’s ballot after the voting session has ended.

Los Angeles County is working closely with our Technical Advisory Committee, that includes national experts in the field of election technology, design and research, to ensure the will of the voters is accurately reflected in election results. Central to this assurance is the voter’s ability to verify that the BMD accurately recorded the voter’s selections on the paper ballot. It also implemented a security architecture that uses secure boot and trusted computing to minimize the chance that unauthorized and/or malicious software could be installed on the device.


The BMD ballot is printed on specially coated thermal paper designed to be durable enough to ensure retention throughout the legally required period associated with the election. An official tint and watermark for the election, provided by the California Secretary of State (SOS), is printed on the back of the ballot. The BMD ballot has four areas of information, as can be seen in Figure 1 below.

Demonstration Ballot

Figure 1. Sample of a voted and printed BMD ballot.


The QR code is a widely used, open format for encoding data in a resilient two-dimensional barcode. Since it is an open format, there are numerous free applications that are publicly available for scanning and decoding a QR code, so that the contents may be read. Any voter can use a QR code reader to scan the Vote Selections QR code on their ballot and verify that the selections in the QR code are match the selections printed on the ballot.

Visual Ballot Inspection

As an example, when the Vote Selections QR code printed on the ballot shown in Figure 1 is scanned by a QR code reader, the following data will appear:


This data is stored as a string of text organized in a key-value pair format designed for the BMD. The table in Figure 2 provides a breakdown and description of the key-value pairs in the example above.

Key Value Description
VER A Version of the VSAP key-value format
SEL 4N/4E/H/J/3C/3K/35/4S/45/3Z/4A/X /3Q/3S/3U/3W/3Y/N/Y The vote selection IDs listed in the same order as those printed on the ballot
BMD 0000046 Device ID of the BMD
SIG 4R57D5C44QKEJRS3OBF33PL0Z6U9TH BR74NTA1VVHK09E6NFDH4DWXPY8Q9ZF6VD 0LAQ1E6IY6AGQC1S4TG095N8NEN3AFOET12 The digital signature applied to the data in the Ballot Activation and Vote Selection QR codes by the BMD security module

Figure 2. Description of key-value pairs encoded in the Vote Selections QR code.

QR Code Independent Audit

Voters can also go online to check the values of vote selection IDs that are contained in the QR code. The values to be checked are only contained in the SEL key values in the QR code (see text in red above). To do so, voters can go online here. The webpage shows the SEL key values and the respective values in human readable text (in English). Voters can use browser’s search mechanism to perform searches of SEL key value and see their respective value.

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