Crypto art is limited-edition digital art, cryptographically registered with a token on a blockchain. Tokens represent a transparent, auditable origin and provenance for a piece of digital art. Blockchain technologies allow tokens to be held and securely traded without the involvement of third parties. Crypto art draws its origins from conceptual art: sharing the immaterial and distributive nature of artworks, the tight blending of artworks with currency, and the rejection of conventional art markets and institutions. The authors propose a collection of viewpoints on crypto art from different actors of the system: artists, collectors, galleries, art historians and data scientists. A set of emerging themes and open challenges surfaces.