At last, an (alleged) criminal smart enough to use a privacy coin instead of Bitcoin.

A US naval officer and his wife tried to sell America’s prized nuclear submarine secrets to a person they believed was a representative of a foreign power in exchange for the cryptocurrency Monero, court documents allege.

Jonathan Toebbe, 42, and his wife Diana, 45, were arrested in West Virginia on espionage-related charges on Saturday after he allegedly placed a memory card at a “dead drop” location in the state.

Court documents indicate that Toebbe used excellent operational security while carrying out encrypted chats with the supposed foreign representative.

But during several months of correspondence, the nuclear engineer was actually emailing an undercover FBI agent, the DOJ alleges.

Toebbe had anonymously mailed a package to a foreign government in April 2020, offering classified US Navy information.

The package included encryption keys for ProtonMail, an end-to-end encrypted service based in Switzerland.

But rather than reply, the unspecified foreign government sat on the offer for seven months before turning over to their FBI attache last December, the FBI affidavit alleges.

An undercover FBI agent struck up a correspondence with “Alice,” who requested US$100,000 in Monero, a privacy coin that is believed to be near-impossible to track.

“This form of gift protects both of us very well,” “Alice” wrote to the undercover agent.

“I am very aware of the risks of blockchain analysis of BitCoin and other cryptocurrenices, and believe Monero gives both [of] us excellent deniability.”

The FBI sent Toebbe a total of US$100,000 in Monero in three different payments between June and August, while he left the agent encrypted SD cards concealed within a peanut butter sandwich, a chewing gum package and a Band-Aid wrapper.

Toebbe said he wanted a total of US$5 million in Monero for all the classified data.

“The complaint charges a plot to transmit information relating to the design of our nuclear submarines to a foreign nation,” said Attorney General Merrick B. Garland.

“The work of the FBI, Department of Justice prosecutors, the Naval Criminal Investigative Service and the Department of Energy was critical in thwarting the plot charged in the complaint and taking this first step in bringing the perpetrators to justice.”