Fangorn is a practical implementation of a Witness Encryption scheme (Garg et al). This scheme allows users to specify conditions against which they encrypt their data. The ciphertext is then made publicly available via IPFS. When someone wishes to decrypt this data, they must prove (provide a witness) that they meet the criteria for data access. Data decryption is a trustless and non-interactive process in which the encryptor and decryptor do not directly interact for decryption to occur.