Shielding “Smart” Contracts Presented By: Kashif Mehboob Khan, Ph.D. Shafaque M. Khan, Ph.D. 

How “smart” a smart contract is? 

Across Wallet Transaction Syncing Peer Mining Node Wallet Transaction Node Wallet Addresses Local Blockchain Blockchain A runtime Environment for EVM Compatible Smart Contracts Across Wallet Transaction Syncing Peer Mining Node Wallet Transaction Node Wallet Addresses Local Blockchain Across Wallet Transaction Syncing Peer Mining Node Wallet Transaction Node Wallet Addresses Local Blockchain Across Wallet Transaction Syncing Peer Mining Node Wallet Transaction Node Wallet Addresses Local Blockchain .. … …… ……. ……….. Incoming Transactions Immutable Byte Code Generation From SC Transactions Existing State SC Code Hash SC Storage Hash ………………………………. New State Formation PPP: Proposed Provenance Layer for Publishing Byte code Based Patterns for New State PPP: • Proposes to generate pattern using mapping from OP Code. • The layer may act as a knowledge-base (by other SC) for white listing certain accounts for trust worthy transactions. • Patterns contains sender & SC address. P2P Blockchain Network Abstract Model for Securing Blockchain from Malicious Smart Contracts 

Implementation Approaches • We may have a smart contract for deploying all other incoming smart contracts OR We may make it manadotory for all the new smart contracts to cal functions from our proposed smart contracts. • Making use of APIs for generating Provenance layer using Remote Clients (such as programmable JSON Based RPC Remote Clients), acting as a continuous running agent on chain. 

Execution Layer • Every byte code needs to verify itself from PPP (Byte Code Pattern) layer even after deployment. • PPP may be on-chain or off-chain, depending upon the data retrieval model type of network & also how/where to retain the latest state of chain. • Every time when a SC is invoked, the new state is not computed unless its pattern is not cleared by Proposed layer 

Outcomes • May be linked with reputation model to build trust worthy transactions on the go (real time) • A contract may be stopped to execute even after its deployment once its pattern is added to the provenance layer. 

Thanks!