Ari Juels, a Professor at Cornell Tech (Jacobs Institute) and former Chief Scientist of RSA, joins us to discuss his work two of his blockchain-related research topics: Authenticated Data Feeds for Smart Contracts and criminal smart contracts. One of the shortcomings of decentralized smart contracts is their inability to retrieve information from the outside world. Smart contracts can’t make API calls to websites and data feeds, but rely on oracles to feed real-world information to the chain. This potentially requires a high trust in the oracle operators. Authenticated data feeds promise to solve the problem by relying on Intel’s novel SGX hardware. We also talked about how criminals could use smart contracts to more efficiently conduct crimes such as incentivizing the theft of private keys or even soliciting real-world crimes such as murder. Topics covered in this episode: Ari’s background in cryptography and cryptocurrencies The pain points with oracles as we describe them today The idea behind Authenticated Data Feeds The hardware and software architecture of the Authenticated Data Feed model and how hardware isolation works How Authenticated Data Feeds could be used to create criminal smart contracts The differents ways in which criminals could use Authenticated Data Feeds to release bounties for crimes such as private key theft or even murder Countermeasures to fight criminal smart contracts The Initiative For Cryptocurrencies & Contracts (IC3) and its raison d’être Episode links: Ari Juels' website Town Crier: An Authenticated Data Feed for Smart Contracts (white paper) The Ring of Gyges: Investigating the Future of Criminal Smart Contracts (white paper) IC3 - The Initiative For Cryptocurrencies & Contracts CCS 2016: Criminal Smart Contracts Talk Zero Days: Stuxnet Documentary This episode is hosted by Brian Fabian Crain and Sébastien Couture. Show notes and listening options: epicenter.tv/164

Few crypto projects have gotten as much attention and caused as much controversy as Steem. The blockchain-based social media platform launched early this year and managed to gain real user traction building up a vibrant community of contributors. The Steem token quickly entered bubble territory reaching a market cap of almost $400m and losing 90% of its value since. Steem Co-Founder and CEO Ned Scott joined us to discuss the ambition of the project and its short tumultous history. We also discussed some of the accusations against Steem and its unorthodox launch. Topics covered in this episode: How Steem was launched out of the BitShares community The different components and tokens of the Steem system How Steem rewards content contributors The controversial Steem launch and criticisms of the project Why Steem transitioned from Proof-of-Work to Proof-of-Stake The potential disbalance of power due to the Steem distribution How Steem managed to build a vibrant user community Episode links: Steem Website Steemit.com Why Every Blockchain Needs a Constitution Charlie Shrem Article on Steem Launch The History of Steem Launch in Words of Dan Larimer Bitcoin Talk Thread on Steem Launch Bitcoin Stackexchange: What is Steem? This episode is hosted by Brian Fabian Crain and Sébastien Couture. Show notes and listening options: epicenter.tv/162