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Process Quality Review (0.7)


Final score:90%
Date:21 Jul 2021
Audit Process:version 0.7
Author:Nick of DeFiSafety
PQR Score:90%


Scoring Appendix

The final review score is indicated as a percentage. The percentage is calculated as Achieved Points due to MAX Possible Points. For each element the answer can be either Yes/No or a percentage. For a detailed breakdown of the individual weights of each question, please consult this document.

The blockchain used by this protocol

Very simply, the audit looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here is my smart contract on the blockchain
  • You can see it matches a software repository used to develop the code
  • Here is the documentation that explains what my smart contract does
  • Here are the tests I ran to verify my smart contract
  • Here are the audit(s) performed to review my code by third party experts

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2021. Permission is given to copy in whole, retaining this copyright label.

Code And Team


This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here.

1. Are the executing code addresses readily available? (%)

Answer: 100%

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Addresses in mainnet.json, in discord or sub graph, etc
Address found but labeling not clear or easy to find
Executing addresses could not be found

2. Is the code actively being used? (%)

Answer: 100%

Activity is over 10 transactions a day on contract ContractRegistry.sol, as indicated in the Appendix.

Percentage Score Guidance:
More than 10 transactions a day
More than 10 transactions a week
More than 10 transactions a month
Less than 10 transactions a month
No activity

3. Is there a public software repository? (Y/N)

Answer: Yes

Is there a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction, it gets a "Yes". For teams with private repositories, this answer is "No"

Score Guidance:
There is a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction.
For teams with private repositories.

4. Is there a development history visible? (%)

Answer: 100%

With 4836 commits and 11 branches, this is a healthy software repository.

This metric checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Percentage Score Guidance:
Any one of 100+ commits, 10+branches
Any one of 70+ commits, 7+branches
Any one of 50+ commits, 5+branches
Any one of 30+ commits, 3+branches
Less than 2 branches or less than 30 commits

5. Is the team public (not anonymous)? (Y/N)

Answer: Yes

For a "Yes" in this question, the real names of some team members must be public on the website or other documentation (LinkedIn, etc). If the team is anonymous, then this question is a "No".



This section looks at the software documentation. The document explaining these questions is here.

7. Are the basic software functions documented? (Y/N)

Answer: Yes

The basic software functions of Bancor Protocol are well documented in "Developer Quick Start"

8. Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 100%

Every single software function of Bancor Protocol is fully documented. Developer, architecture, API, SDK, and other

Percentage Score Guidance:
All contracts and functions documented
Only the major functions documented
79 - 1%
Estimate of the level of software documentation
No software documentation

9. Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 71%

Code examples are in the Appendix. As per the SLOC, there is 71% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Percentage Score Guidance:
CtC > 100 Useful comments consistently on all code
90 - 70%
CtC > 70 Useful comment on most code
60 - 20%
CtC > 20 Some useful commenting
CtC < 20 No useful commenting

10. Is it possible to trace from software documentation to the implementation in code (%)

Answer: 100%

There is clear and explicit traceability between Bancor Protocol's documented software functions and their subsequent implementation in their source code. Good examples of this traceability are the Developer Quick Start, and the API Reference

Percentage Score Guidance:
Clear explicit traceability between code and documentation at a requirement level for all code
Clear association between code and documents via non explicit traceability
Documentation lists all the functions and describes their functions
No connection between documentation and code



11. Full test suite (Covers all the deployed code) (%)

Answer: 100%

Code examples are in the Appendix. As per the SLOC, there is 261% testing to code (TtC).

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Percentage Score Guidance:
TtC > 120% Both unit and system test visible
TtC > 80% Both unit and system test visible
TtC < 80% Some tests visible
No tests obvious

12. Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 90%

Bancor has received v2 code coverage from ConsenSys Diligence in their audit report. However, it is not the full coverage and does not explain misses or uncovered lines.

Percentage Score Guidance:
Documented full coverage
99 - 51%
Value of test coverage from documented results
No indication of code coverage but clearly there is a reasonably complete set of tests
Some tests evident but not complete
No test for coverage seen

13. Scripts and instructions to run the tests? (Y/N)

Answer: Yes

14. Report of the results (%)

Answer: 100%

Detailed test report was found here, as well as a more extensive report in the ConsenSys Diligence audit report.​

Percentage Score Guidance:
Detailed test report as described below
GitHub code coverage report visible
No test report evident

15. Formal Verification test done (%)

Answer: 0%

No evidence of a Bancor Formal Verification has been found in their documentation or in web searches.

16. Stress Testing environment (%)

Answer: 100%



This section looks at the 3rd party software audits done. It is explained in this document.

17. Did 3rd Party audits take place? (%)

Answer: 100%

Bancor Protocol has had multiple audits before deployment, both V1 and V2, as well as 2.1. A full list of reports can be found here.

Percentage Score Guidance:
Multiple Audits performed before deployment and results public and implemented or not required
Single audit performed before deployment and results public and implemented or not required
Audit(s) performed after deployment and no changes required. Audit report is public
Audit(s) performed after deployment and changes needed but not implemented
No audit performed
Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address not found, (where question 1 is 0%)
Deduct 25% if code is in a private repo and no note from auditors that audit is applicable to deployed code.

18. Is the bug bounty acceptable high? (%)

Answer: 70%

​Bancor's Bug Bounty program is active and offers up to 100k for the most critical of finds.

Percentage Score Guidance:
Bounty is 10% TVL or at least $1M AND active program (see below)
Bounty is 5% TVL or at least 500k AND active program
Bounty is 5% TVL or at least 500k
Bounty is 100k or over AND active program
Bounty is 100k or over
Bounty is 50k or over AND active program
Bounty is 50k or over
Bug bounty program bounty is less than 50k
No bug bounty program offered
An active program means that a third party (such as Immunefi) is actively driving hackers to the site. An inactive program would be static mentions on the docs.

Access Controls


This section covers the documentation of special access controls for a DeFi protocol. The admin access controls are the contracts that allow updating contracts or coefficients in the protocol. Since these contracts can allow the protocol admins to "change the rules", complete disclosure of capabilities is vital for user's transparency. It is explained in this document.

19. Can a user clearly and quickly find the status of the access controls (%)

Answer: 100%

The Bancor Protocol governance portal is clearly indicated on their website.

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Access control docs in multiple places and not well labelled
Access control docs in multiple places and not labelled
Admin Control information could not be found

20. Is the information clear and complete (%)

Answer: 50%
  • a) All contracts are clearly upgradeable through the DAO. 30%    - b) Bancor has a multisig through which it appears DAO changes are implemented 20%    - c) Capabilities for change not clearly described. 0%

Percentage Score Guidance:
All the contracts are immutable -- 100% OR
a) All contracts are clearly labelled as upgradeable (or not) -- 30% AND
b) The type of ownership is clearly indicated (OnlyOwner / MultiSig / Defined Roles) -- 30% AND
c) The capabilities for change in the contracts are described -- 30%

21. Is the information in non-technical terms that pertain to the investments (%)

Answer: 90%

All governance and access control-related information is usually explained in user-friendly words.

Percentage Score Guidance:
All the contracts are immutable
Description relates to investments safety and updates in clear, complete non-software language
Description all in software specific language
No admin control information could be found

22. Is there Pause Control documentation including records of tests (%)

Answer: 0%

There is no evidence of Pause Control or a similar function documented in the Bancor documentation.

Percentage Score Guidance:
All the contracts are immutable or no pause control needed and this is explained OR Pause control(s) are clearly documented and there is records of at least one test within 3 months
Pause control(s) explained clearly but no evidence of regular tests
Pause controls mentioned with no detail on capability or tests
Pause control not documented or explained


 The author of this review is Rex of DeFi Safety.

Email: rex@defisafety.com
Twitter: @defisafety

I started with Ethereum just before the DAO and that was a wonderful education.  It showed the importance of code quality. The second Parity hack also showed the importance of good process.  Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.
I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development. DeFiSafety is my full time gig and we are working on funding vehicles for a permanent staff.

2 * @dev This contract maintains contract addresses by name.
3 *
4 * The owner can update contract addresses so that a contract name always points to the latest version
5 * of the given contract.
6 *
7 * Other contracts can query the registry to get updated addresses instead of depending on specific
8 * addresses.
9 *
10 * Note that contract names are limited to 32 bytes UTF8 encoded ASCII strings to optimize gas costs
11 */
12contract ContractRegistry is IContractRegistry, Owned, Utils {
13    struct RegistryItem {
14        address contractAddress; // contract address
15        uint256 nameIndex; // index of the item in the list of contract names
16    }
1718    mapping(bytes32 => RegistryItem) private items; // name -> RegistryItem mapping
19    string[] public contractNames; // list of all registered contract names
2021    /**
22     * @dev triggered when an address pointed to by a contract name is modified
23     *
24     * @param _contractName    contract name
25     * @param _contractAddress new contract address
26     */
27    event AddressUpdate(bytes32 indexed _contractName, address _contractAddress);
2829    /**
30     * @dev returns the number of items in the registry
31     *
32     * @return number of items
33     */
34    function itemCount() public view returns (uint256) {
35        return contractNames.length;
36    }
3738    /**
39     * @dev returns the address associated with the given contract name
40     *
41     * @param _contractName    contract name
42     *
43     * @return contract address
44     */
45    function addressOf(bytes32 _contractName) public view override returns (address) {
46        return items[_contractName].contractAddress;
47    }
4849    /**
50     * @dev registers a new address for the contract name in the registry
51     *
52     * @param _contractName     contract name
53     * @param _contractAddress  contract address
54     */
55    function registerAddress(bytes32 _contractName, address _contractAddress)
56        public
57        ownerOnly
58        validAddress(_contractAddress)
59    {
60        // validate input
61        require(_contractName.length > 0, "ERR_INVALID_NAME");
6263        // check if any change is needed
64        address currentAddress = items[_contractName].contractAddress;
65        if (_contractAddress == currentAddress) {
66            return;
67        }
6869        if (currentAddress == address(0)) {
70            // update the item's index in the list
71            items[_contractName].nameIndex = contractNames.length;
7273            // add the contract name to the name list
74            contractNames.push(bytes32ToString(_contractName));
75        }
7677        // update the address in the registry
78        items[_contractName].contractAddress = _contractAddress;
7980        // dispatch the address update event
81        emit AddressUpdate(_contractName, _contractAddress);
82    }
8384    /**
85     * @dev removes an existing contract address from the registry
86     *
87     * @param _contractName contract name
88     */
89    function unregisterAddress(bytes32 _contractName) public ownerOnly {
90        // validate input
91        require(_contractName.length > 0, "ERR_INVALID_NAME");
92        require(items[_contractName].contractAddress != address(0), "ERR_INVALID_NAME");
9394        // remove the address from the registry
95        items[_contractName].contractAddress = address(0);
9697        / if there are multiple items in the registry, move the last element to the deleted element's position
98        / and modify last element's registryItem.nameIndex in the items collection to point to the right position in contractNames
99        if (contractNames.length > 1) {
100            string memory lastContractNameString = contractNames[contractNames.length - 1];
101            uint256 unregisterIndex = items[_contractName].nameIndex;
102103            contractNames[unregisterIndex] = lastContractNameString;
104            bytes32 lastContractName = stringToBytes32(lastContractNameString);
105            RegistryItem storage registryItem = items[lastContractName];
106            registryItem.nameIndex = unregisterIndex;
107        }
108109        // remove the last element from the name list
110        contractNames.pop();
111        // zero the deleted element's index
112        items[_contractName].nameIndex = 0;
113114        // dispatch the address update event
115        emit AddressUpdate(_contractName, address(0));
116    }
117118    /**
119     * @dev utility, converts bytes32 to a string
120     * note that the bytes32 argument is assumed to be UTF8 encoded ASCII string
121     *
122     * @return string representation of the given bytes32 argument
123     */
124    function bytes32ToString(bytes32 _bytes) private pure returns (string memory) {
125        bytes memory byteArray = new bytes(32);
126        for (uint256 i = 0; i < 32; i++) {
127            byteArray[i] = _bytes[i];
128        }
129130        return string(byteArray);
131    }
132133    /**
134     * @dev utility, converts string to bytes32
135     * note that the bytes32 argument is assumed to be UTF8 encoded ASCII string
136     *
137     * @return string representation of the given bytes32 argument
138     */
139    function stringToBytes32(string memory _string) private pure returns (bytes32) {
140        bytes32 result;
141        assembly {
142            result := mload(add(_string, 32))
143        }
144        return result;
145    }

Solidity Contracts


Comments to Code: 4050 / 5680 =  71 %

JavaScript Tests


Tests to Code: 14816 / 5680 = 261 %