Earlier this month, Lavabit and Silent Circle – two privacy-minded email providers – decided to shut up shop rather than give the US government the chance to access their customer data. Shortly thereafter, Lavabit owner Ladar Levison told Forbes, “If you knew what I knew about email, you might not use it.”
This weekend, Silent Circle’s Louis Kowolowski dropped the cryptic comments and explained a major, inherent vulnerability with email: metadata.
While encryption technologies like PGP and SMIME can be used to obscure the actual contents of a message, assuming you use a desktop program that supports encryption software, current email protocols don’t allow you to secure the “header” metadata details that are used to shuffle email from point to point. The sender, recipient, subject, date and time, and even server path information is all sent along in clear text.
That’s enough to be a liability to people who truly need privacy, according to Kowolowski.
“If your goal is to not have metadata leakage in your otherwise secure communications, you may wish to avoid email altogether. Email leaks the information about who is communicating, and how often. This information may be just as damaging as the content of the email,” he said.
Snowden’s leaks have shown that the U.S. government is aware of the power of metadata. The NSA collects Verizon’s phone records to examine metadata and analyze call patterns, and the government does not need individual warrants to do so, as courts have classified metadata as “transactional data” rather than actual communications. Again, here’s Kowolowski:
“With the tapping of backbone internet providers, interested parties can now see all traffic on the internet. The days where it was possible for two people to have a truly private conversation over email, if they ever existed, are long over,” he said.
Since text, video, and messaging communications don’t suffer from the same header needs as email, they’re able to be secured from end-to-end, with all encryption and decryption handled on the client machines–and indeed, Silent Circle still offers “Silent Phone,” “Silent Eyes,” and “Silent Text” services that do just that. Check out our guiding to protecting your PC from Prism surveillance for more privacy-minded tips and tricks, or if metadata security means less than the message itself, read PCWorld’s guide to securing your email.