The use of encryption is growing and its benefits are obvious, but that doesn’t mean you’ll fly under the radar according to a document signed by U.S. Attorney General Eric Holder and published by the Guardian.

If the NSA determines the data collected on you involves “communications that are enciphered or reasonably believed to contain secret meaning,” then you can bet they’ll keep that data indefinitely. “Such communications can be retained for a period sufficient to allow thorough exploitation and to permit access to data that are, or are reasonably believed likely to become, relevant to a future foreign intelligence requirement.”

That encryption exception is just one of many outlined in the document, which also allows the NSA to give the FBI and other law enforcement any data from an American if it contains “significant foreign intelligence” information or information about a crime that has been or is about to be committed. Americans’ data can also be held if it’s “involved in the unauthorized disclosure of national security information” or necessary to “assess a communications security vulnerability.” Other “inadvertently acquired” data on Americans can be retained up to five years before being deleted.

So when the NSA figures out you’re protecting your privacy using encryption such as PrismCipher, go ahead and figure they’ll keep your message until they can crack it. Further, you should likely assume you and your message recipients might become “persons of interest” in the interim.