Protecting your privacy online is not an easy thing to do, especially when it comes to the prying eyes of the NSA and other spy agencies that have complex tools at their disposal to help them collect massive amounts of personal data. But it turns out there are certain tools that are difficult even for the NSA to hack, a new report from Der Spiegel reveals.

FROM EARLIER: Hackers have found an insanely easy way to steal your fingerprints

The publication gained access to various NSA documents that explained the kind of programs the NSA had troubles decrypting. Apparently, the agency has a scale for online programs, ranking online services according to how difficult they are to decrypt — from “trivial” all the way up to “catastrophic.”

“Monitoring a document’s path through the Internet is classified as ‘trivial,'” Der Spiegel notes. “Recording Facebook chats is considered a ‘minor’ task, while the level of difficulty involved in decrypting emails sent through Moscow-based Internet service provider ‘mail.ru’ is considered ‘moderate.’ Still, all three of those classifications don’t appear to pose any significant problems for the NSA.”

The agency has identified one anonymity method that’s impossible to crack. By combining several services including Tor, VPNs, CSpace and ZRTP, Internet users would give the NSA a “catastrophic” headache, as their communications would be virtually impossible to intercept.

This cocktail leads to a “near-total loss/lack of insight to target communications, presence,” as the NSA explains.

Tor is a web portal that helps users anonymize their traffic, and has been detailed in various reports so far. VPNs (or virtual private networks) and similar anonymizing services are online tools that can be used to hide the user’s actual IP address, and redirect traffic through proxy servers — used alone, these services might not provide the level of security Internet users expect, but they could be more efficient when paired with these other online tools.

CSpace is an encrypted chat service that protects communications and file transfers. And finally, ZRTP is an encryption service for voice calls and texts.

Experts believe that even though the documents were shared internally two years ago, the NSA has not made much progress cracking some of these secure services.

Der Spiegel’s full report, based on this new series of NSA documents leaked by whistleblower Edward Snowden, is available at the source link.