Tech Target (May 7) -- OTA Foundation, the Berlin-based nonprofit behind the IOTA cryptocurrency platform, is gearing up to launch an “internet of things” data marketplace to securely store, sell and access data streams. The secret sauce, or architecture, that differentiates IOTA from other distributed ledgers is its directed acyclic graph called “tangle,” which doesn't rely on blocks.“I haven’t been able to convince myself of its security,” says Andrew Miller, a professor of electrical and computer engineering at Illinois.