The answer to that is tricky because it depends on intent. Taking an expansive definition of blockchain as a log of sequential, cryptographically verifiable tr

The answer to that is tricky because it depends on intent. Taking an expansive definition of blockchain as a log of sequential, cryptographically verifiable transactions seems okay enough. At the point where we're nitpicking what is/isn't blockchain, that's not a useful exercise, because the real question is whether this is the right solution for the right problem. On the other hand, "blockchain" is a highly loaded term, and choosing to label something on the margins "blockchain" means diffusing the legitimacy of application onto the marketing term, or vice versa. In that sense, I'd be hesitant to lump this marginal example into "blockchain" specifically instead of just "cryptography stuff".