This means that since as far back as 2006, a skilled hacker could alter the data on an e-Passport chip—like the name, photo, or expiration date—without fear that signature verification would alert a border agent to the changes. That could theoretically be enough to slip into countries that allow all-electronic border checks, or even to get past a border patrol agent into the US.
"The idea of these things is that they’re supposed to provide some additional electronic security over a standard passport, which can be forged using traditional techniques," says Matthew Green, a cryptographer at Johns Hopkins University. "The digital signature would provide that guarantee. But if it’s not checked it doesn’t."
A letter to CBP on Thursday from senators Ron Wyden of Oregon and Claire McCaskill of Missouri highlights this crucial shortcoming. More than 100 countries now offer passports that come with a digital chip, and fewer than half of those include the capability to verify the integrity of data using a digital signature. But Wyden and McCaskill stress that while the US demands that countries in the Visa Waiver program put a chip in their passports, it has failed to fully realize its own e-Passport program.
"CBP does not have the software necessary to authenticate the information stored on the e-Passport chips," the two Senators wrote. "Specifically, CBP cannot verify the digital signatures stored on the e-Passport, which means that CBP is unable to determine if the data stored on the smart chips has been tampered with or forged."