I had an idea while showering today. I was thinking of how hashcash forces would-be spammers to expend considerable computation effort if they want to spam email servers that use hashcash. This imposes a dollars-and-cents barrier on spamming. This got me to thinking about the fact that, even today, the vast majority of email communications are sent in the clear. If the NSA or Mossad or fill-in-the-blank intelligence agency wants to engage in widespread, ECHELON-style surveillance of emails, the fact that they are sent in unmasked text is a great assistance to the would-be eavesdroppers. Ideally, people might encrypt all communications but it turns out that encryption has a lot of overhead problems. The most significant problem with encryption is key management. If you send me an email and I've lost or misplaced the key, I can't read it. And this brings me to WSREP - Widespread Surveillance-Resistant Email Protocol! Basically, WSREP is implemented by encrypting emails and sendin...