From Chaos to Confidence: Understanding and Predicting Transactions | Charles Guillemet - Ledger

all righty we're getting through Saturday how's everyone doing uh next up we have a very special guest um from one of the sponsors of eth Denver 2025 um yeah please welcome to the stage the CTO of Ledger uh Charles J [Music] [Applause] hello everyone uh my name is Charles G and today I'm going to explain you how to avoid losing 1.4 billion USD uh the name of my talk is from chaos to confidence understanding and prediction and predicting transaction this is what we call blind signing would you sign this the problem is uh you have no idea what this transaction is maybe you are about to sign a transaction you want but maybe you are signing away your wallet so you have no way to understand if it's a legitimate transaction if it's a correct uh smart contract that you're coding this the correct function or if it's a malicious payload or or unintended authorization so this is a big problem uh that we have today this is exactly equivalent as signing a blank check so maybe uh you are interacting with the smart contract you wanted but maybe you are um signing away your wallet and unfortunately this is not like theoretical getting getting scammed isn't Fun uh we have plenty of such examples only in the past 6 months we had was we had a rant hack and more recently buy it and in all this this cases uh the the users uh endpoint or the user UI in the case of save were compromised and at the end the user was blind signing a transaction and the problem is that they they had no idea if they was were signing the transaction they wanted or if they were signing away their wallets and this is EXA exactly what happened last week with bybit and they simply lost 1.4 billion this is the biggest hack ever uh in in the crypto space and unfortunately I think that won't be the last one we will see more and more Z hack and we definitely need to solve this problem again the attacks aren't theoretical at all they used to be uh but now they are completely part of the reality so the only way to solve this problem is to clear signing clear signing is pretty simple the idea is to provide the users with all the information so that he can understand the transaction he is about to sign here this is a 1in fusion Swap and as a user you can understand that you are about to uh interact with this smart contract and you are about to swap 1,000 maic to 500 usdt you have the address of your receiver which which should be used and if everything matches with your intent then you will click on sign and you will sign a transaction it's transparent completely human friendly and it's empowering as a user you have you are completely empowered to decide if you want to sign this transaction or not how does it work so first of all clear signing is not some something new for Ledger uh Ledger was created in 2014 uh at the end that was only uh Bitcoin and U the with the first Hardware wallet we did already had a screen because of this because as a user as a user you want to understand that you are sending 0.1 Bitcoin to this specific address so clear signing was um at the core of what Ledger is offering from the beginning the thing is uh after that we had eum and now Sana and plenty of chains and when when it's only about sending and receiving it's pretty simple to um to support properly clear clear signing because everything is standardized but when it comes to interacting with a smart contract smart smart contracts can be arbitrarily complex and the device has no way to understand how to pass the transaction and how to display the information to the user so we are working on this for quite some time with uh the different uh standard with the EIP 712 with the EIP 191 for message signing and and all of this so this is not something new for us and we will continue working on this it's a never never ending Journey but here for smart contract interaction we built a generic framework that allows to clear sign any single um smart contract if you are familiar with eum you know that smart contract have hbi and and you might think that ABI could be like already a good level of of information that's true ABI are are quite interesting but they are not sufficient because as a user this is plenty of exod decimal stuff you uh don't completely understand the intent uh the name of the method you don't know if the specific parameter is a date or an amount or the type of this this data so AI is already providing plenty of information but we need to be able to uh format them in a human readable way so this is why we have um created a standard which is the EIP 7 7730 and the idea of the standard is to um format this data so that the device can understand them so what we ask is um dab to create a gon file and this gon file will enable the device to understand how to pass the transaction it's human readable lightweight and efficient completely flexible and and extensible and it's completely daa driven and declarative we start with uh the evm because obviously this is the this is where the the action um goes this is where there are plenty of smart contract and and and and such interaction however it's not only um for eum it's really for every single blockchain interaction the so again we have um submitted an ERC 7730 I guess it should be merge now or about to be we discussed with the the foundation yesterday um and there are like three main um three main steps uh for Clear signing to happen the first one is to uh create this uh Json file and to do so either the DAP the protocol call can create the Jon file um independently or we have created um a tool that facilitate the process and then the the the dab the protocol will submit uh a g file on a public registry U so far this is just a GitHub that that that is controlled by Ledger but the idea is really to decentralize this because this is not about Ledger this is really about interacting with blockchain and any single wallet needs this kind of data so we will create we have created a public registry and we will decentralize it uh on the long run and then as soon as we have this uh we will endorse this gon met data file we will verify every single submission and if you think the submission is legitimate then we will sign it and finally um this gon file will be provided uh to the device whenever you uh interact with a smart contract so that the device is is able to um pass the transaction uh properly in order to make it happen again uh we need dap to uh create this Json metadata file uh in order to EAS the process we have created a tool and we need wallets or or app uh to integrate our device SDK uh the device SDK is very simple uh to integrate and then you can um communicate with Ledger devices very easily like you have a only high level API to discuss with the device you can connect it you can get an address you can sign its transaction and only with this high level API you will get clear signing for free so for wallets it's very to very easy to integrate or daps can also integrate the device SDK in their UI in order to have like a direct connection to the device and then you're good to go we have clear signing the device management kit is again is very easy to integrate it allows to discover the devices that are connected to the mobile or to your desktop it allow to connect to Simply exchange data and you have also a state machine that allows to know um in which state the device is and finally you have like high level uh operating system command to launch the eum app to get an address to sign this message to um to sign this transaction and this kind of thing very high level so for wallet and app it's really very easy to integrate again we are working on this for quite some time uh in 2024 we decided that was a big Focus for the company um uh we were quite quite um predictive uh because the all the hacks the big hacks I mentioned happened after uh but the thing is like it's really important for the ecosystem uh to solve this security problem because it's a matter of trust it's a matter for users and for the world to trust our block chain technology uh if blockchain technology is just about hacks and mem coins frankly there is no not much value so what we what we are building is is much more than this so let's solve this security problem together uh I want to give a quick example with a uh so uh we have created the the tool that in mention so you go on the on the address of the tool you input the address of AR this smart contract so this is um this is what we did here and then you click on submit and then on the on the second page you can uh directly fill the metadata so you will create the different screen you will decide which uh fields are important to uh interact with a what are the where where what are the offset to uh find the specific um method and parameters what are the type of the parameters and all of this and then you can preview uh the different screen that will be uh rendered on The Ledger devices at the end it automatically generates the gon file I mentioned and as as a dab as a you only have to uh submit your uh G metadata file uh to the public registry I mention again this is today this is a GitHub repository so this is just a commit on the GitHub repository very easy and then finally you clear sign a so because what we did in the behind the hoods is verifying the submission from H it it comes from a everything seems legit we sign this metadata file and as soon as you are going to interact with a a smart contract um when you are about to sign a transaction the RO transaction is sent to the device along with this metadata file and then the device is able to pass the transaction because it has the context that the that is included in the metadata file and that allows the the device to properly pass this uh transaction and then you are on a uh you interact with a smart contract you are about to borrow 0.5 e and um the interest rate mode is variable and the DOR is this specific address so as a user you understand exactly what kind of transaction you are signing when you are signing this you have like quick cryptographical cryptographic guarantee that you are interacting with a if you sign a hash maybe you are interacting with har but maybe you are signing away 1.

4 billion USD so again as I mentioned we started with u this journey uh a long time ago with u with send and receive and staking and so on uh but in 2024 we really focused on evm and um and we have created this um this standard uh also uh we are going to support uh ERC 7702 uh day one so this is something that is ongoing um so that after that you will be able to uh interact with u with smart wallet in a clear in the clear signing way uh this is something ongoing uh we have created this 77 30 um ERC that allows anyone to uh to support the DB and clear sign the transaction so any wallet can use it again not only about Ledger and uh we are going to continue working on this with other chain um with Solana for instance with Cosmos with near and also on bitcoin I want to mention Bitcoin because now on bitcoin you have plenty of new interaction with tab scripts and they are even more difficult to pass for our devices so this is uh this is only the beginning of the Journey but really the the purpose of all this um stream is to secure the ecosystem understanding this transaction is really a big Improvement a big Improvement but it may not be uh enough because uh your transaction might remain um harmful with clear signing as a user you are able to understand what kind of smart contract you're calling what what are the method What will what you will do but you have no idea on what will be executed at the end and for this um I'd like to introduce with uh a new uh security uh level with a transaction check so the idea of a transaction check is to um prevent malicious transaction to be signed and it provides a warning to user when there is a a threat detected that that would be like a malicious function address poisoning abusive permits and it's completely compl ment with clear signing and if ever there is a there was threat detected on the device you will be prompted with this kind of warning and either you uh decide to um to sign this transaction anyway so it's a it's at your own risk or you can be back to safety without siging this transaction how does it work again it's pretty simple um whenever you are interacting with this new shiny dab then uh the the transaction to be signed is crafted on the UI and just before signing it it's signed it's sent uh to a trusted third party that are simulating the transaction uh simulating the execution of the transaction and they conduct a risk analysis of this specific transaction and they be they will issue a risk assessment for this specific transaction this risk assessment is signed by by this third party and it will be sent uh to the device the device is is able to clear sign the transaction and uh it will also display the risk associated to this transaction on the device because it it will be able to verify that this risk assessment report matches with the transaction to be signed so this would be like the kind of um um warning that you can have uh when there is a no uh threat detected like everything uh seems okay you can even uh click on the on on the on the on the icon on the top so that you have like more information why no threat was detected and if you there is a sweat that is detected then uh you have this um this screen uh you can uh click on the on the icon at the top you will have a QR code and then you scan the QR code you end up on the website that explains you why um this transaction has been detected as a critical threat and then you decide either you sign this transaction uh anyway and then uh you might have an issue or uh you have uh simply saved um part of your wallet which is good news so again uh we really want to stop all this hacks unfortunately the attackers outside out there won't stop here they will continue trying to twak users they will continue to hack frontend they they will continue to hack smart contract and as an industry as an an ecosystem we really need to uh stop this because uh it's really a matter of trust it's a matter of credibility for our industry uh so uh I really want to uh call any everyone in the room everyone in the Stream to help us uh solving this uh big issue and to prevent the next big hacks so if you want to help us uh you can uh go on this useful link so we have a developer portal that will give you all the information uh if you want to contribute if you are a wet uh it's really a matter of integrating our uh device SDK that will do everything under the wood and the device management is far easier using this device SDK and if you are a Dap uh you we will we need your help to um create this metadata file as you see as you saw as I mentioned it's pretty easy for a Dap to to do this um and I really think it's important that dap does it because they are the one who knows best uh how their smart contract works I don't want to do it for a I really want that a does it for for for for their smart contract so thank you for your attention and um and uh yeah let's secure the ecosystem