ERC-20 token standard contains a major logical flaw — lack of communication model (lack of transaction handling model). This problem is well-known. I wrote tens of articles on Ethereum reddit, gitter and github during the past 6 years. Starting from this post. Also, here is Vitalik Buterin’s comment on this. …

ERC-20 is the oldest (and the first) Ethereum “token standard” — a documentation of a template of a token that everyone can use to create new tokens. ERC-20 defines two methods of transferring tokens: transfer function — a “push” transaction of a token. approve function that authorizes someone to perform…

A couple of word about myself I am Dexaran, a founder of EthereumCommonwealth team, security auditor, hacker (I have DDOSed EOS mainnet in 2019 and froze its DAPPs for half a year and drained Chintai exchange). Founder of Callisto Security auditing organization. We have audited more than 300 smart-contracts and not even a single one that…

This article describes the implementation of https://github.com/Dexaran/CallistoDAO and how it is different from the original TheDAO. Callisto DAO is based on the source code of TheDAO that was hacked in 2016 and caused Ethereum-ETC split. The original DAO whitepaper can be found here. 1. Updated syntax / Solidity version The original DAO contract was written 7…

The Immortal Lottery is an autonomous smart-contract that implements a fully decentralized gambling APP on-chain. Without any third parties involved, without any off-chain non-verifiable sources of entropy. You can read more about the Immortal Lottery details here. The lottery is deployed on Callisto Network mainnet: Entropy contract 0xad4e8434649BDa8bD2fF27e2e3E5a49BC3d5A661 Lottery contract…

Recently, artificial intelligence has received serious development. In some areas, neural networks can already compete with humans. For example, Midjourney can already produce high quality images and ChatGPT can write or analyse fragments of code. Callisto Team is pioneering the adoption of neural networks in security area to automate the…

Exploit overview On 6 October 2022 an attacker tricked Binance Bridge to issue 2M BNB (worth ~$550M at that moment). The attacker then used the “printed” BNB as a collateral to borrow multiple other assets and transferred them to other EVM-compatible chains. Approximately $130M worth of assets were moved out. The rest…

Callisto Network is launching an “early adopters SBT campaign”. You can now request your SBT by commenting on the following twitter thread: https://twitter.com/CallistoSupport/status/1598317345738481667 What are SBTs? SoulBound Tokens are non-transferable NFTs that you can own, but cannot give to anyone else. The point is that we have a type of “valuables” in…

Exploit overview On October 11, 2022 the DeFi protocol TempleDAO was exploited. About $2,3M worth of funds were withdrawn from the platform contract at that time. The amount is 4% of the total amount of funds involved in the TempleDAO. The attacker then moved the funds to TornadoCash. Here is the invocation…