# Decentralized Storage and Zero Leaks Communication - Costanza Gallo | Web3Privacy Now

- Speakers: [Costanza Gallo](https://streameth.org/speakers/costanza-gallo)
- Channel: [Ethereum Cypherpunk Congress](https://streameth.org/ethereum-cypherpunk-congress)
- Date: 2024-10-09
- Duration: 17:48
- Topics: web3, privacy, swarm, ethereum, ethrome
- Watch: https://streameth.org/watch/yt-QUdoGolheLQ
- YouTube: https://www.youtube.com/watch?v=QUdoGolheLQ

## Description

Web3Privacy Now | Community 1st - Rome Takeover (5/10/23) - ETHRome 2023
Decentralized Storage and Zero Leaks Communication
Costanza Gallo: https://twitter.com/costgallo | Business Developer at Swarm: https://www.ethswarm.org/

Web3privacy Now is a think-and-do tank made by individuals who care about digital privacy and individual rights. Its primary objective is to explore, spotlight, and evaluate privacy-centric goods and services within the web3 domain.

Twitter: https://twitter.com/web3privacy
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Filmed & Edited by BabyBit Production: https://twitter.com/BabyBitProd

## Transcript

[Music] so okay uh my name is costan and I'll be talking about the centralized St and zero disc Communications a little bit about me um I work for the Swarm Foundation the centralized and chancellorship resistant storage and communication Network H the focus today it is PSS messaging so how that enables to have communications that can be leaked um someone before say that the NSA can track everything down maybe we can talk about it later so before I start a disclaimer first of all I'm not a lawyer and talking about legal advice and also I'm not a coder so do your own research so without further Ado today we're going to see first of all a small personal anodot on why I care about privacy why it is important to me personally then we will see the swm networks and the key elements that are fundamental to the worm Network and how those elements come into play to generate zer communication so let's start why do I care about privacy first of all because it is universal but what does it mean I have a background in anthropology and privacy as we know it it is not Universal because every culture has a different view of what should be private and what can be public also the concept of privacy is ever evolving as technology and surveillance Technologies and fortunately Advanced things that we used to take for granted are no longer private but nonetheless every culture values keeping something private and what is private and what is not will be up to you and not to any say second there is no freedom without privacy and this goes without saying and finally because it's so [ __ ] E to break it um my father was a cist a satirical cartoonist a very dangerous threat to the nation you know um and for this reason we often had our mobile and landline under surveillance um whenever I would call him um they were like normal rings then there was a weird sound and then again normal two two two now that was super easy to spot because it was in the 90s early 2000s and so it was very easy and just because the police were monitoring him they we knew everything about my teenage crash and that was kind of like freaking me out but also like I feel super bad for the police officer that was monitoring me because I was super lame yeah so you know the governments needed to monitor him because they need to protect us from terrorism and danger and this is an example of why my father was considered dangerous so today I'm going to speak about how worm enables dualist communication thanks to the PSS messaging worm is a decentralized communication and storage system it provides a scalable and self sustaining infrastructure for a supply chain of data a bit of context PSS is the whisper verion of bbz of BZ the voiceless and hard to hear sound of BM and it also pays all much to whisper the ethereum's original dark messaging protocol that was part of the Holy Trinity back in 2014 with ethereum whisper and swm before going into that we will see a few K elements of worm that are fundamental to achieve theas communication so so we will explore B noes the basic building blocks of the war networks we will see chunks chunks are the smallest unit of data in SW when a file is uploaded on the network it gets divided into small chunks and each chunks is store in multiple B noes so even if one or more B noes are compromised the data will still be available and finally we will see the Academia routing which sounds like a bad word it is a distributed Ash that it is used to find the location of chunks in the SW Network so the tagline here is that swm achieves releas communication by storing encrypted chunks of content in the bin noes that communicate using the Academia routing and mixing them up so what does it mean so the B notes worm is a peer-to-peer Network the is no single node controll the network and each one of us can run their own their own node each node is assign an address which is distinct from the network address and notes a group in the neighborhoods so you can configure your B noes into four way the getaway mode the ultra light the light and the full node now the getaway and the ultral light they don't allow for PSS messaging the light note allows for PSS messaging but you don't participate fully in the network and the full node is the best way to join the network because it allows full functionalities chunks so in swarm when you upload a chunks from a file to a website to a video it is split into small chunks and they are split all across the world to important things each hunk of data is addressable via a hash and it is distributed to more than one node so it is redundant by default and when you upload a file you can decide whether to encrypt it or not so if a requestor is authorized to assess a chunk it must be in possession of the decryption key while an authorized parties cannot so this is the encryption scheme and it is designed to be independent of the chunk store layers that means that the same infrastructure can be used to store both encrypted chunks and un encrypted chunks the only difference that for one you need the encryption key and that has three main advantages the first one is that it is easy to switch between encrypted and non-encrypted data the second one is that it is possible to use the same chunk to store for both public and private data and finally it reduce the amount of code to be maintained and written so the Academia routing um the Academia routing ensures that each node connects to a specific subset of nodes in a ways that it gets efficient this is very important so for the no Boer of the chunk it is not possible to find out who is requesting a given chunk or who is storing a given chunks um so in this way you have ambiguity of context and you don't have leak metadata providing with what we call plausible deniability so how does it work in step one you have the message that it goes to the pier to the P that is known to be the nearest and in the same way in step to it goes and it moves forward so in this way there is no way to know where the request is coming from and where the request is orating so you can have the relas communication browsing and Publishing so now that we have the building blocks time to see how the zero Le communication Works PSS provides for a PP sub facility that can be used for a variety of tasks ns are able to listen to messages receive for a specific Topic in the nearest neighborhood and create messages that are destined to be in another neighborhood using swarmm data dissemination protocol and to do so we have four keywords encryption troyan chunks handshake and Anonymous mailbox so troan chunks why do we need them so we say that linking the sender from the recipent is impossible but like someone um spoke about before there is traffic analysis that can give away so in order to overcome that you need a very high volume of traffic or fake traffic so what happens is worm is that it masks the messages as normal Chun traffic and up with create a message the act of messaging itself in other words fine Waldo so how does it work here we have Dave that wants to send a message to Alice Dave knows the publicy of Alice and he encrypts the message using Alice publicly they wrap the message in a troan message and obtain the Cyber tax payload of the troan chunk with the symmetric encryption then they founds random ones and the destination Target is a bit sequence that represents the neighborhood where Alice belongs so they've uploads their chunks to worm and it gets synchronized to Ali's neighborhoods how does Alice receive the message um Alice only knows that the trunk is a TR message is a PSS message if and when she opens the troan message with a private key corresponding to the public key that they knows and he does an Integrity topic uh matching forwarding notes so anyone in between Alice and Dave have no idea to know whether that was a tro method or whether that was a random encrypted method so communication in that way is perfectly op fiscated as generic TR trunk traffic so in the sense we can say that troyan chunks allows you to have disguise traffic encrypted messages are disguise like any normal piece of traffic and that makes it virtually impossible for third parties to track or intercept messages because to an observer the encrypted PSS messaging looks like any other piece of innocent and inoc form traffic Anonymous mailbox so if Al is not online then the Chun will prevail like any other Chun depending on how much it's been paid to stay on the sworm network so in other words the troan message provides asynchronous mailbox functionalities without any further action from the and the handshake when Alice meet Alice me Dave encrypted communication requires a handshake at the very beginning in order to agree on the initial parameters that are used as inputs to the symmetric ke generation scheme so the protocol is set out to allow two pares to establish a Shar secret uh the Shar Secret secret from the input used to determine the encryption key which will be used during the P handshake two WS messaging so again we have Dave that starts the communication with Alice and we have Alice that advertise the information necessary for Dave to be in contact to have Z Communications you need first to perform a handshake to establish the fit key and then to with the indexing methodology used so after that we have a prek bundle AKA all the information that Dave needs to know about Alice so Dave needs to invite Alice to an outbox feed private Communication channel and the first step to do so is to ask for her public prey bandle feed and send an initial message to say hey I want to communicate with you so after that they sh the parameters required to initiate the encrypted communication the public key of his long-term identity and the public key generated only for that conversation and those details are delivered to Alice by sending a troan CHS now both parties have all ingredient that they need to generate the triple Dy Helman share secret aka the S key for the double racket continuous key agreement protocol as using signal protocol the scheme provides forward secrecy and post compromise security to the end to endend encryption and this is important because by adding forward and backward secrecy to the outbox the communication channel is completely fiscated so it gives three components to the messaging obfuscation deniability of the channel and this gu us messages in other words we have zero L communication now imagine you want to send a secret message to your friend vitalic but you don't want anyone else to see it here is what you will do you will issue a stamp address envelope by finding a unique code announc that when is used to create a special package has an address close to balic address you pay for the Posta stamp and you encrypt the package with a lock that only vitalic nose and you wrap it up as a troan chunks then what happens on vitalic side uh it receiv receives the troan message containing the encrypted package vitalic uses the private key to unlock and decrypt the message vitalic verifies the postage stamp to ensure that it is valid and the code represents the address of the package and I confirm that the code matches their own address to ensure that the package is actually you know intended for them so when vitalic wants to send you back a message um it will follow the steps it will encrypt a message with your public key creating again a secret package they wrap up the package as a troan method and create a unique code that generates an address close to yours the sign the tro message using the private key creating a signature the package up everything together in a special envelope with a stamp address and a signature and finally they send the envelope with a poster stamp to ensure that it gets delivered and you do the same you receive the envelope you verify post touch stamp to make sure that it is actually intended for you and you open it and honestly here you can find my contacts and War contacts um I wish we had this form of little this communication back when I was a teenager so thank you very much and thank you all for coming here [Applause] [Music] today