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Summary
TenX introduces a security token. The token implements the ERC-20 and ERC-1400 (ERC-1644 and ERC-1594) specifications. It grants the right to receive Y% (Y = amount TENX tokens owned by an account / total amount of TENX tokens) of the PAY tokens which are deposited in the rewards contract by TenX. An eligible user can withdraw his share of PAY token from the reward contract. A user is eligible if he passed KYC and held TENX token when the deposit was made.
The new token standard (ERC–1400) which TenX uses is currently in development and thereby subject to changes. Therefore, ChainSecurity Ltd recommends TenX to track the latest developments related to this standard.
The TenX smart contracts have been analyzed with state-of-the-art tools for verification of generic vulnerabilities and custom functional requirements. During this process, ChainSecurity Ltd found several issues of different severity (see report for full details). All reported issues were then dully acknowledged and addressed by TenX.
About TenX
TenX is a Singapore-based blockchain company that makes cryptocurrencies spendable on-the-go. The TenX payment system includes the TenX Wallet that can be funded with different cryptocurrencies (available on iOS and Android) and the TenX Card, which can be used in almost 200 countries.
Find out more at tenx.tech.
Summary
During the investigation ChainSecurity Ltd noted that the project is of high quality, employs good coding practices and has clean code. Despite the system’s complexity the DAO maintain a clear overall structure thanks to the high degree of modularity and low coupling between components.
The system’s specifications were verified against a set of general and adversarial assumptions and an attacker model. As a result ChainSecurity Ltd was able to uncover several security vulnerabilities of varying severity as well as propose design optimizations and improvements. Most notably, a missing verification check would allow beneficiaries to redeem their reputation multiple times.
Finally, ChainSecurity Ltd remarks that all vulnerabilities and issues were professionally and swiftly addressed by the DAOstack team leading to a more resilient, efficient and secure system.
About DAOstack v2
DAOstack powers decentralized companies, funds and markets to make fast and innovative decisions at scale. It’s a platform for decentralized governance that enables collectives to self-organize around shared goals or values, easily and efficiently. DAOstack is sometimes called an operating system for collective intelligence, or a Wordpress for DAOs.
Find out more about DAOStack at daostack.io
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Summary
The DAO voting system itself turned out to be well implemented and of high quality, in its functionality mostly following the previously published Governance whitepaper. A high degree of modularity was achieved in the code base introducing a clear overall structure.
Nonetheless, ChainSecurity Ltd managed to uncover several vulnerabilities and propose design improvements. Most notably, an unfortunately still common misuse of the EXTCODESIZE was originally present: Namely, using this opcode to detect that the message sender or transaction initiator is not a contract account, but an externally owned account. Given that such checks can be easily circumvented, this restriction cannot be relied upon to enforce proper access control even though there may be benign use cases. For more information of this,we are glad to point to the Smart Contract Best Practices to which ChainSecurity Ltd contributed for this issue.
As for the roles present in the DAO system, these distinguish mainly between the Digix administrative roles, initiators of proposals which are to be voted on by other users and finally the voters themselves. An overview of the roles and their conditional rights is provided in the
introductory section of the audit report.
Finally, ChainSecurity Ltd remarks that all vulnerabilities and issues were professionally and swiftly addressed by the Digix team and we are now curiously following further development and adoption of the project.
About Digix
Digix is one of the world’s first Smart Asset companies and aims to be the leading brand in tokenizing the world’s tangible assets.
Learn more about Digix Dao at https://digix.global/dgd/
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Summary
Switcheo is creating a decentralized exchange (DEX) where users can trade Ether and any ERC20 tokens. Before being able to trade on the exchange, users have to deposit their ETH and/or ERC20 tokens to the Switcheo platform. To initiate transactions, users have to first sign the trade data off-chain. This signed data is then sent to Switcheo, which initiates transactions on the DEX on users’ behalf.
ChainSecurity Ltd analyzed the Switcheo smart contracts under different aspects, with a variety of tools for automated security analysis of Ethereum smart contracts, including Securify, and manual expert review. Overall, we found that Switcheo employs good coding practices and has a clean code base. Nonetheless, ChainSecurity Ltd was able to uncover several security, design, and trust issues that were successfully mitigated or addressed by Switcheo before deployment.
About Switcheo
Switcheo Network is the first decentralized exchange on the NEO blockchain which now allows trading of Ethereum and NEO tokens. Switcheo’s goal is to achieve a DEX network with cross-chain swapping capabilities across popular blockchains, with a focus on delivering a world-class trading experience in a trustless and decentralized environment.
Find out more about the project at https://switcheo.network/.
Summary
When contracted by STACK, ChainSecurity Ltd conducted an extensive review of STACK’s multi-token smart contracts with the help of several (internal and external) tools. Throughout this process, multiple issues including two critical security issues were uncovered. All of the security issues were promptly addressed by STACK and pose no further security threat.Furthermore, in cooperation with ChainSecurity Ltd, STACK made additional optimizations to the contracts’ design and their trust model resulting in a more efficient and more trustworthy set of smart contracts.
About STK
STACK is a new personal finance platform, built on the idea that using your money should be free. Universally accessible, STACK is an alternative to traditional banking that allows you to store your money safely, access it instantly and transact with it anywhere, in any currency including crypto, right from your smartphone. The STK Token will provide instant cryptocurrency payments at point of sale, enabling seamless integration of cryptocurrency into everyday transactions and financial services in the STACK wallet. The STK token will be implemented on the public Ethereum blockchain as an ERC20 token.
Find out more about STACK at stktoken.com.
Summary
Republic Protocol is a decentralized open-source dark pool protocol facilitating atomic swaps between cryptocurrency pairs across the Bitcoin and Ethereum blockchains. Trades are placed on a hidden order book and are matched through an engine built on a multi-party computation protocol. While the order matching engine is placed off-chain, trade orders themselves are first encrypted and committed on-chain and then later revealed after matching. This ensures that once the information becomes public the trade already happened and allows to monitor matching nodes for malicious activity and retrospectively challenge their bond when they were misbehaving.
Our audit investigated the Republic Protocol itself, which allows for custom settlement solutions to be used by future participating brokers, as well as the reference implementation of a full Dark pool by the team called RenEx. During the investigation ChainSecurity Ltd noted that the project is of high quality, employs good coding practices and has clean, well-documented code which is impressive considering the complexity of the project.
While the audit was scoped, a specification covering core parts of the system was derived by both teams and verified under a set of general and adversarial assumptions and an attacker model. All of the previous is clearly defined in the whitepaper and audit report. ChainSecurity Ltd was able to propose several design optimizations and improvements, but more so uncover several vulnerabilities of varying severity. These were swiftly reviewed and addressed by the Republic Protocol team, leading to a more resilient, efficient and secure system.
We are excited to follow the further development of the Republic Protocol and the adoption of their trading pools.
About Republic Protocol
Republic Protocol is a dark pool platform designed for trading large volumes of cryptocurrencies.
Ren is powered by a decentralized network of Darknodes that use secure multiparty computation to run privacy preserving applications. Using it, they are building hidden order books and privacy preserving settlement layers.
Dark pools built on Ren are the first in the history of financial markets that are mathematically provable to be fair.
Find out more here: https://renproject.io/
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Summary
WBTC is an ERC20 token that represents Bitcoin as an (extended) ERC20 token on the Ethereum blockchain, where 1 BTC equals 1 WBTC token. The involved entities are at least one custodian (the current setup is tailored to exactly one) and multiple merchants. The whole system has in general two main tasks:
- Minting WBTC:
If a matching amount of BTC is locked at a custodian’s account (on the Bitcoin blockchain), the corresponding amount of WBTC tokens is minted (released) to the merchant (on the Ethereum blockchain). - Burning WBTC:
When a merchant wants to convert his WBTC tokens back into BTC, he places a burn request (the specified amount of WBTC tokens are burned). If successful, the custodian sends the merchant the requested amount of BTC (on the Bitcoin blockchain).
To accomplish a Bitcoin-to-WBTC swap and back, a merchant sends BTC to a custodian. The custodian confirms that this merchant has deposited a certain amount of BTC on the Bitcoin blockchain. A matching amount of WBTC is then minted by a custodian and can be used by the merchant. Accordingly, if a merchant wants to swap back the WBTC to BTC, the merchant files a request to burn the WBTC. The custodian transfers the BTC back to the merchant, if the burning of the WBTC was successful.
Overall, the smart contracts request and record the transaction details on the Ethereum blockchain. Actual transactions of BTC are happening on the Bitcoin blockchain. Other tasks include managing (adding/removing) merchants and custodians.
Our audit investigated the code implementation issues arising from the management of merchants and custodians, as well as from the minting, transferring, and burning of the WBTC token on the Ethereum blockchain.
Overall, the ChainSecurity Ltd team found that Wrapped Bitcoin is a very well-coded smart contract with clean documentation. During the audit, we detected two security issues concerning (1) the pausing of the minting/burning process (2) and a possible hash collision. The hash collision was possible due to using abi.encodePacked() instead of abi.encode(). Chainsecurity also highlighted relevant trust assumptions arising from the overall system setup. WBTC addressed, acknowledged or fixed the raised issues. Therefore, ChainSecurity Ltd sees no remaining security issues in the current version.
About Wrapped Bitcoin (WBTC)
WBTC (Wrapped Bitcoin) will launch as a fully backed Bitcoin ERC20 token on Ethereum in January 2019. The initiative will bridge Bitcoin liquidity and the decentralized ecosystem on Ethereum, enhancing all decentralized applications. WBTC will allow the Ethereum network to be leveraged to enable new applications and use cases for Bitcoin.
WBTC is a community focused initiative and is the culmination of a long-standing joint effort relationship between BitGo, Kyber Network, and Republic Protocol. Prominent decentralized exchanges and financial projects, including MakerDAO, Dharma, Airswap, IDEX, Compound, DDEX, Hydro Protocol, Set Protocol, Prycto, RadarRelay, Blockfolio and Gnosis have all committed to support the adoption of WBTC and will participate as launch members.
For more information please visit www.wbtc.network
Summary
The stablecoin is collateralized 1:1 by the US Dollar and its implementation is realized as a ownable ERC20 token. Paxos Standard 18-decimal PAX is designed to be upgradeable, using the ZeppelinOS Upgradeability with unstructured storage library for this purpose.
ChainSecurity Ltd analyzed the Paxos Standard smart contracts under different aspects, with a variety of tools for automated security analysis of Ethereum smart contracts including Securify and manual expert review.
Overall, the ChainSecurity Ltds auditors found that Paxos employs good coding practices and has clean, well-documented code, which is well covered by a corresponding test suite. Nonetheless, ChainSecurity Ltd was able to uncover several minor issues and vulnerabilities related to the Security and Design of the system which Paxos successfully addressed and resolved before launch. The successful collaboration between the Paxos and ChainSecurity Ltds teams improved the overall security and reliability of the Paxos standard.
About Paxos
Paxos is building a future where all assets — from money to commodities to securities — will be digitized and can move instantaneously, 24/7. Settlement risk will cease to exist, so trillions of dollars of trapped capital can go to work in a global, frictionless economy. Today, as the first regulated Trust company with blockchain expertise, Paxos is uniquely positioned to mobilize and custody assets digitally. Visit www.paxos.com for more information on Paxos and its institutional-grade products like Paxos Standard token and Paxos Confirmation Service for precious metals.
Summary
POA Network is building a Proof of Authority sidechain to Ethereum to facilitate secure, fast, and cheap transactions while being fully compatible with the existing Ethereum ecosystem. A cross-chain bridge allows easy transfer of tokens from a POA Network chain onto the main Ethereum chain and vice-versa. The POA Network system consists of many connected open-source components. Smart contracts form the core and give strong guarantees, dApps and APIs allow for easy access and a custom parity client is running an efficient Proof of Authority based version of Ethereum using the Aura consensus. The audit focused on the core part, the smart contracts deployed on POA Network.
Our audit investigated technical issues such as the initialization of keys and their distribution, the requirements of the validator set, and the upgradability of the smart contracts. We also looked into the reward system and the overall governance to check their soundness and design.
Overall, the ChainSecurity Ltd team found that POA Network is a very well-coded complex system with clean documentation. During the audit, several issues have been found by ChainSecurity Ltd and successfully addressed by POA Network. ChainSecurity Ltd sees no remaining security issues in the current version.
About POA
POA Network is an Ethereum-based platform that offers an open-source framework for smart contracts. Towards the end of 2017, POA Network launched its own blockchain utilizing a new and unique consensus mechanism known as Proof of Authority (POA). POA leverages an independent group of validators who are all licensed public notaries around the United States which increases security while enabling a method of governance on the blockchain. POA Network is scalable, secure and cheaper than other projects, aiming to provide a platform for small and medium sized organizations.
For more information please visit https://poa.network/
Summary
Kyber is building The Decentralized Liquidity Network that powers instant and seamless inter-token transactions between platforms, ecosystems, and other use cases. By allowing open contribution of liquidity from token holders and easy integration from DApps and projects to leverage the contributed liquidity pool, Kyber enables a more connected tokenized world where tokens are liquid and useful.
These interesting properties of Kyber’s platform make the smart contract security non-trivial. Kyber has a detailed trust model that combines upgradability and trustworthiness, an achievement that is rarely seen. In particular, users are protected by the proxy contract from misbehaving administrators or exchanges. This is because the proxy contract enforces a minimal conversion rate while still allowing upgrades to the underlying business logic.
Overall, the ChainSecurity Ltds team found that Kyber’s platform is well-designed. Moreover, the implementation of the smart contracts is clean, follows best practices and guidelines, and comes with an extensive test suite. During the security audit, the ChainSecurity Ltds team made several minor recommendations, which have been addressed by the Kyber team and so we see no remaining security issues.
About
Kyber is a decentralised exchange which provides a seamless user experience with high security. Kyber guarantees liquidity, allowing users to convert or transfer tokens instantly. Users can trade directly from their wallet, without having to register or deposit beforehand.
Learn more about Kyber at kyber.network.
Summary
The iExec smart contracts constituting the Proof-of-Contribution protocol have been analyzed under the agreed upon specification, with different tools for automated security analysis of Ethereum smart contracts and manual review. The issues listed in this report result from ChainSecurity Ltd’s verification of this specification and should not be considered exhaustive.
While we found that iExec employs good coding practices and has clean, well-documented code, the current Proof-of-Contribution implementation has a model that places trust in external contracts and key roles, introducing several issues.
For details please see the full technical report.
About iExec
iExec is inventing the internet of the future by developing the first Blockchain-based, fully decentralized cloud computing platform. iExec aims to provide blockchain-based distributed applications a scalable, secure and easy access to the computing resources required for their execution. It uses the blockchain to organize a market network where everyone can monetize their servers, applications, and data-sets.
Summary
ChainSecurity Ltd. has analyzed Zilliqa’s smart contract and has found no major technical vulnerabilities or shortcomings. The ZIL smart contract contains the necessary token functionality. Zilliqa has additionally addressed the minor shortcomings that were uncovered during the report and has even implemented some of the recommendations.
About Zilliqa
Zilliqa is a new public blockchain platform for high-throughput applications. It brings the theory of sharding to practice with its novel protocol that increases transaction rates as its network expands. The latest experimental results demonstrate a throughput of more than 2,400 transactions per second, which is over 200 times higher than that of today’s popular blockchains. The platform is tailored towards enabling high-throughput data-driven decentralized apps, designed to meet the scaling requirements of applications in areas such as digital marketing, payment, shared economy and rights management. Zilliqa has been under research and development for two years, with several commercial applications in different sectors.
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Summary
Augur is a decentralized prediction market that runs on top of the Ethereum blockchain. The Augur platform estimates the probability of future events based on votes casted by users, thereby leveraging the wisdom of the crowd principle. Users are rewarded whenever they make correct predictions
The scope of the security audit conducted by ChainSecurity Ltd. was restricted to scanning of the contracts for generic security issues using automated systems and manually inspecting the results, followed by 32 hours of manual audit of the contracts for security issues.
About Augur
Augur is a decentralized prediction market that runs on top of the Ethereum blockchain.
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Summary
In the following we describe the V Token (VEE) and its corresponding token sale. Table 1 gives the general overview.
The VEEs are allocated in two phases. The TGE starts with a contribution phase during which contributors invest ETH. The contribution phase is split into pre-sale and main sale. Each of these sales is capped at USD 20M. The cap itself is not automatically enforced within the smart contracts. After the contribution phase, the TGE continues with a token allocation phase during which the price of tokens is determined and each contributor is allocated with tokens based on their contribution.
About Block V
BlockV provides a platform for creating smart digital objects (vAtoms) on blockchains and distributing them among users.
Summary
ChainSecurity Ltd. has audited the HelloGold Tokens (HGT) contracts. As part of the audit, ChainSecurity Ltd. identified several issues. The HelloGold team has been fast and professional, they were able to fix most of the issues quickly through code changes. Some of the issues, which are harder to address on a technical level, will be addressed through other means. Overall ChainSecurity Ltd. is not aware of any remaining issues in the HGF contracts.
About HelloGold Foundation
HelloGold is a startup that creates simple and accessible gold products for everyone. Founded in 2015 and headquartered in Kuala Lumpur, Malaysia, HelloGold built the world’s first Shariah-compliant gold digital application that changes the way people buy and sell gold. The company’s platform features state-of-the-art online security and is supported by fully audited processes to guarantee proper ownership of the physical gold. HelloGold’s team of seasoned professionals have come together from the gold industry, financial services, technology and digital user experience, all with the aim of making gold available to everyone in Asia.
Summary
The most critical subjects covered in our audit are escalation of privileges, functional correctness, and trustworthiness. Security regarding escalation of privileges is good.
In a previous iteration, the issues Manager Can Steal Bridged Assets via Deliberate Non-Fill and No Rate Limit on Operator Enables Repeated Slippage Loss were identified; both have been addressed in the latest version. Security regarding functional correctness is good after issues such as Queued Safe Transaction Can Invalidate Accounting Snapshot and Incoming Token Transfers Corrupt Slippage Check have been addressed.
To resolve the latter, Makina changed the specification to ban management instructions that can yield execution control to an attacker, who could exploit it to mask a loss, see Restrictions on Whitelisted Management Instructions. This places considerable responsibility on the user, who must carefully review all management instructions before whitelisting them. Security regarding trustworthiness is good: the trust model is layered and well-defined, with the Safe retaining ultimate control and neither the Provider nor infrastructure roles able to move funds out of the Safe. The general subjects covered are specification and code complexity. Security regarding both is high.
In summary, we find that the codebase provides a good level of security.
It is important to note that security audits are time-boxed and cannot uncover all vulnerabilities. They complement but don't replace other vital measures to secure a project.
About Makina Lite
Makina provides Makina Lite, a Gnosis Safe module through which authorized operators manage DeFi positions, harvest rewards, swap tokens, and bridge tokens to other chains on behalf of a user who stores their assets in the Safe. The user has to whitelist all operations that can be performed.
Makina Lite operates in one of three modes: operators are fully trusted in OPEN mode, while FENCED and WALLED add increasing protection against a malicious or compromised operator through slippage limits and cooldowns.