Inspired by the article The future of Ransomware and its description of possible ransomware with verifiable key delivery, I wonder if the idea can be taken further into ransomware that credibly threatens publication unless a payment is made, yet verifiably destroys the data if it receives payment.
Let us first make some (probably not entirely reasonable) assumptions:
- The attacker can maintain control, despite attempts of the security community, of sufficient network resources to exfiltrate data from infected computers with internet connection at a rate of, say, 10 Gbit/s globally (i.e. the bandwidth from all victims combined), and resources to store all data downloaded over that connection.
- The attacker possesses a decent heuristic for detecting blackmail-worthy files. The idea is just to avoid almost all of the downloaded data being worthless junk like Windows swap files. (Though it would probably be impossible to avoid the security community deliberately feeding junk designed to trigger the heuristic.)
Would it be possible for a sufficiently motivated attacker to develop ransomware using modern CPU "secure enclave" technologies and e.g. Ethereum that encrypts files and transmits them to the attacker, but in such a way that the attacker can only choose to either decrypt the files or to receive payment, but not both?
For example, is it possible for the attacker to verifiably create an enclave that he runs on his backend computers that either allows releasing funds transferred to an account securely created inside it or to decrypt the files, have that enclave attest itself to the ransomware, and to publish the code running in that enclave so that others can verify that functionality?