Ekiden Paper: https://arxiv.org/pdf/1804.05141.pdf
enigma paper: https://enigma.co/enigma_full.pdf
Extend blockchain smart contracts through off-chain logic https://www.ibm.com/developerworks/cn/cloud/library/cl-extend-blockchain-smart-contracts-trusted-oracle/index.html
sgx tutorial https://github.com/dingelish/SGXfail
Sgx-based secure container https://scontain.com/
sgx paper collection https://github.com/vschiavoni/sgx-papers
Related to secure flow calculation: https://www.comp.nus.edu.sg/~shuhao-z/secure.html