sofie-erc721 v1.0.1

Smart contract for ERC-721 based access tokens. Details can be found in:

N. Fotiou, I. Pitarras, V.A. Siris, S. Voulgaris, G.C. Polyzos, "OAuth 2.0 authorization using blockchain-based tokens," Proceedings of the NDSS 2020 Workshop on Decentralized IoT Systems and Security (DISS), San Diego, CA, USA, 2020 view paper