The Department of Homeland Security is testing blockchain technology to secure cameras and other devices at U.S. ports of entry, including borders and airports. The goal is to better detect and stop intruders who try to impede the devices or manipulate the data they collect.

DHS runs thousands of devices in airports, at ports, and on the U.S. borders with Mexico and Canada, including sensors that detect movement and temperature changes, X-ray machines, and video and still cameras. On a typical day, U.S. Customs and Border Protection, which is a law enforcement group within DHS, screens one million travelers and 67,000 cargo containers, and makes 1,100 arrests related to immigration, drug trafficking and trade violations.

Kevin McAleenan, deputy commissioner of Customs and Border Protection. Photo: Department of Homeland Security

While sensors are useful for detecting border activity, especially in areas where human guards are not continuously stationed, Internet of Things networks can be vulnerable, said Kevin McAleenan, deputy commissioner of Customs and Border Protection.

The blockchain project is, in part, intended to thwart spoofing, where someone tries to divert data moving over a network, or to control devices on the network, by mimicking authorized senders or receivers. The idea is to better protect data exchanged between the devices and human agents guarding borders, Mr. McAleenan said.

A blockchain distributed ledger can store identifying details about a transaction permanently, securing them cryptographically so that they cannot be changed. Stored on a blockchain, device data, which could include visual and other types of information about travelers and goods moving across U.S. borders, would be safe, said Peter Kirby, chief executive of Factom Inc., a startup working on the project. A future application of the technology could be in maintaining the integrity of data to be used later as evidence in prosecutions, he said. “Data and images have to hold up in court,” he said. “This lets multiple parties agree on a single version of the truth.”

Late last year, Factom and Customs and Border Protection completed a small project to prove that blockchain technology can secure data from sensor-equipped devices. Now they are further testing the security and speed of the technology for handling extensive IoT feeds, he said. Factom received a $199,000 grant from DHS in last June.

The agency could put blockchain ledgers into wider use, perhaps in international trade to verify the provenance of goods coming into the U.S. and international travel to identify high-risk flyers and speed up security checks for common travelers, Mr. McAleenan said.

Private-sector blockchain projects, including Wal-Mart Stores Inc.’s work to secure its pork and produce supply chains, could help guide the Customs and Border Protection work, he said. Wal-Mart and International Business Machines Corp. are building blockchain systems in China and the U.S. to make food supply chains more efficient and secure. Wal-Mart is a large part of international trade for the U.S. “When they’re looking at something to make their supply chain more efficient, that’s something that gets our attention,” he said.