Please note that at this point in time we are restarting and accelerating the K Ethereum Virtual Machine (KEVM) program only. The IELE program will be coming very soon.
IELE is a dedicated virtual machine that provides a foundation for the Cardano blockchain protocol. It executes and verifies smart contracts as well as provides a human-readable language for blockchain developers. IELE was designed using formal methods to address security and correctness concerns inherent in writing Solidity smart contracts in Ethereum. When you write a smart contract in IELE, it is more secure and is easier to verify for correctness. You benefit from an easy-to-use and readable language structure - and the overall performance is improved.
The IELE devnet provides better performance and is register-based, which means it can make use of a wider array of analyses and optimizations than a stack-based virtual machine such as KEVM. This leads to more accurate gas cost predictions, as well as lower gas cost for contracts.
IELE is a human-readable language that resembles the LLVM intermediate representation. This makes it easy to code directly to IELE, as well as to understand contracts and how they are deployed in the blockchain. IELE is designed to make formal verification of smart contracts easier. This includes writing specifications that smart contracts must obey as well as helping develop automated techniques that prove smart contracts are mathematically correct. For example, pushing a possibly computed number on to the stack and then jumping to it as an address makes verification hard, and thus security weaker, with current smart contract paradigms. IELE avoids this problem. It has named labels and jumps can only be made to those labels. Also, avoiding the use of a bounded stack and eliminating stack or arithmetic overflow helps the specification and verification of smart contracts.
Debugging contracts is easier because IELE has a different status error code for each of the exceptions that can occur while executing the functions within a contract. The sender of a transaction that calls a function receives a status code as a return value in addition to the normal return values of the account call.