Town Crier system is an authenticated data feed for smart contracts, a.k.a. an "oracle." It was created by students and faculty at The Initiative for CryptoCurrencies and Contracts (IC3).
Smart contracts systems today lack trustworthy sources of data, as currently deployed oracles provide only weak provenance and confidentiality assurances. The Town Crier system leverages trusted hardware (Intel SGX) to provide a strong guarantee that data comes from an existing, trustworthy source. It also provides confidentiality, enabling smart contracts to support confidential queries and even manage user credentials.