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Questions tagged [privacy]

Questions related to data and smart contract privacy. For questions related to user anonymity, use [tag:anonymity].

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1answer
116 views

Data privacy with block chain in health care?

I'm new to the concept of block chain and have only been reading about it the past four hours. I hear a lot of marketing and business folks tell me that block chain is the way of the future for data ...
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2answers
198 views

Which wallets lets you generate multiple ethereum addresses?

Is there a wallet that lets you generate multiple ethereum wallet addresses? I don't like the fact that I only use one address and that everyone can see what I have. Or are there other ways to keep ...
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1answer
196 views

How do private members work?

The solidity documentation says that Everything that is inside a contract is visible to all external observers. Making something private only prevents other contracts from accessing and ...
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1answer
59 views

Enigma “secret contract” and concealing transactions history: How is it possible?

Enigma protocol is a second-layer, off-chain network that aims to solve privacy issues in blockchain. However In Enigma blog, there is an article (Link to Article), explaining the secret contract, ...
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1answer
47 views

ENS Domains and new receive addresses for privacy

Currently I use a new receive addresses every time I receive ETH - Ledger Live creates new receive addresses by default when an address has been 'used' as this is good practice in terms of privacy. ...
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1answer
29 views

What mathematical concepts do I need to master in order to understand the Aztec Procotol?

What mathematical concepts do I need to master in order to understand how privacy in the Aztec Protocol works? When I look at the white paper, I have no idea what is going on; however, I am confident ...
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2answers
44 views

How to listen to inter-node communications regarding transactions

If I run a full node (say geth) in the Ethereum network, then the way things work out is that every node releases/ announces new transactions as they receive new ones. I'm assuming that my node must ...
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2answers
46 views

Auction contract privacy

I have an auction contract, where bidders bid with Ether then me (owner) select which offer is most suitable and thus this bidder is contract winner. Once the winner is selected, I send him data as a ...
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1answer
25 views

Privacy concern

I have a smart contract where user submit data based on a task set by the owner, post doing so the owner in another contract offers this data to the highest bidder. Is it possible to ensure the ...
2
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1answer
48 views

Save temporarily-shareable private data using Quorum

Can we use Quorum (or any other Ethererum variation) to save private data that can be shared with other parties for a temp period? The use case is that: A patient can share his medical data that is ...
3
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2answers
213 views

Confidential value transfers

Is there currently any way to do confidential transactions with Ethereum for a custom token? If not, is there any work/research being done on how this might be possible?
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1answer
30 views

Data integrity and privacy [closed]

I have a crowd sensing system where user after checking the task I provide for a location x, sends temperature values to the contract of that location. I've been trying to a way to implement data ...
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4answers
1k views

With a ring signature mixer, will Ethereum transactions be completely anonymous?

I was reading the Serenity PoC2. The part quoted below grabbed my attention. Does it imply full anonymity for Ethereum transactions should I decide to use the ring signature mixer? Ring signature ...
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1answer
49 views

User anonymity while submitting data in smart contract

I've written a smart contract, that is a crowd sensing system. Where post posting a task user view that task and if they have what I'm asking for/and meet the task requirements they submit certain ...
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1answer
23 views

How does Ethereum ensure that “users can own their data, and your apps don’t spy and steal from you”? [closed]

What features in ehtereum would ensure that the Dapp would never spy on you or steal your data?
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2answers
888 views

Issue with New version of Metamask: Remix cannot detect the Metamask address

I have just installed Metamask version: 6.3.1 Now in Remix, the address of my account in metamask is not detected. The account box in remix remains always blank now (see picture below). Note that I ...
26
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3answers
4k views

zk-SNARKs vs. Zk-STARKs vs. BulletProofs? (Updated)

zk-SNARKs, Zk-STARKs and BulletProofs are three major zero knowledge proofs to provide privacy for the blockchain technology. If we can compare them, (1) Bulletproofs and Zk-STARKs require no ...
8
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2answers
353 views

When a smart contract is deployed, is its source code publicly viewable?

When a smart contract is deployed to the blockchain, is the source code then publicly viewable to all participants? For example, what you see here in Etherchain. I am aware that there are some ...
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1answer
53 views

How would zkSNARKs reduce computation on Ethereum mainnet?

cmiiw, zkSNARKs mean that computations can be verified by a single node and therefore not executed by every node on the network-- link, and work is being done to include this feature in the mainnet. ...
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0answers
29 views

What are the drawbacks of layer 2?

The scalability trilemma states that a blockchain can only have two out the following three properties: decentralization, scalability, and security. Layer 2 protocols aim to make Ethereum more ...
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3answers
1k views

Confidentiality in Blockchain

Can Blockchain miners see confidential transaction information? Since they have the public key, they decrypt the transaction for the purpose of verification. So if I am mining in Ethereum, I can tweak ...
4
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1answer
490 views

Ethereum facilitation for zk-SNARKs

There has been a lot of talk about leveraging zk-SNARKs to bring privacy features to the Ethereum Blockchain. My question is, how is Ethereum facilitating the verification of zk-SNARKs at the moment, ...
1
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1answer
277 views

ZK-SNARKS with ZoKrates - problems with proving the hash preimage tutorial

Just noticed today that ZoKrates has finally support for SHA256! I wanted to see it in action, so I followed the tutorial at https://zokrates.github.io/sha256example.html with a slight modification of ...
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0answers
15 views

Encrypt and anonymize communication

I want to anonymize the communication between participants (communication = exchange of data, not currency). This should have the effect that two participants send messages to each others but now ...
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0answers
23 views

Ethereum fork with Ring Signature at the core layer

Today we can have Ring Signature at the contract-level. https://github.com/HarryR/solcrypto/blob/master/contracts/UAOSRing.sol I wanted to know if there is any fork or project that would like to ...
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2answers
109 views

Is it safe to commit truffle build files to Github (open source)?

Regarding the json build files that Truffle produces based off of my smart contract, is it safe for this information to be treated as public? I just want to be sure it doesn't contain any sensitive ...
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4answers
222 views

Is it possible to obscure the owner of a non-fungible token?

Basically, I'd like to have unique records which can be transferred between parties without anyone knowing who owns a particular record until a transfer occurs, at which time only the recipient can ...
2
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1answer
160 views

zk-SNARK use cases in blockchain (except payment)?

Is there other examples of using zk-SNARK for supporting "private transactions" except Zerocoin or Zchach ? (For example, is it possible to use zk-SNARK for health data ? or any other use cases in ...
6
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2answers
371 views

Updated: Is it possible to hide the sender or receiver of transactions by “zk-SNARK” or “Bulletproofs”?

To support the user privacy, is it possible to hide the sender address or receiver address of transactions by "zk-SNARK" or "Bulletproofs" ? Or we’ll be able only to hide the value that is mapped to ...
2
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1answer
38 views

Masking Ethereum Address in a transaction [duplicate]

I want to hide the ethereum addresses of dApp users so that your transactions will not be traced by one who you have interaction earlier. The use case is actually similar to the application: Alice ...
1
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1answer
32 views

Parameter's Value visibility

Is the value of a contract's method's parameter visible on blockchain? On Etherscan, in the tx information there is an Input Data field, which details says The binary data that formed the input of ...
2
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1answer
373 views

How privacy can be ensured in smart-contracts?

When a smart-contract is created following an agreement between two entities, how the state of that contract (data) can be kept secret to only the two contractors? I heard about Quorum, but how ...
0
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1answer
120 views

Is data inputted as a parameter for a smart contract function visible?

Let's say I have something like this: bytes32 person; function registerPerson(address _person) public { bytes32 x; x = sha256(abi.encodePacked(_person)); person = x; } For privacy reasons, ...
0
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1answer
44 views

Implementation of privacy in blockchain

How can we see transactions in a particular block of Bitcoin, if they are encrypted and only Merkle root of transactions is stored on the blockchain. I think in that way we should be having an ...
11
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3answers
4k views

Is there any way to hide a transaction?

Is there any way to hide a transaction on the Ethereum blockchain? Some blockchain have protocols that implement this by default, like Monero and Zcash. Is something similar possible on Ethereum?
20
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2answers
3k views

Private info in an Ethereum smart contract

Is there any way to store info on a smart contract, and keep it a secret? If a contract has a state variable that is not public like: contract foo{ uint public publicVariable; uint notPublic;...
9
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1answer
627 views

What data will zk-SNARKs protect?

Implementing zk-SNARKs is planned in Ethereum roadmap, what data will be obfuscated? transaction sender and receiver? data in transactions? data stored in contracts? variables and methods in ...
1
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2answers
46 views

Is there any way to fund a new account privately via a randomising pool?

It isn't currently possible to create a new HD wallet account and privately fund it, is it? I'm aware of this thread, but I'm not asking about SNARKs. Instead, I'm curious if there's any way to send ...
0
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1answer
83 views

Privacy-preserving smart contracts: examples, tutorial, best practices?

I want to make a proof-of-concept about privacy-preserving smart contracts. I know it's uneconomical to use encryption with Ethereum smart contracts. Are there best practices about how to do that? ...
2
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1answer
689 views

An example on using “zk-SNARK” in “smart contract”?

I read this article: https://media.consensys.net/introduction-to-zksnarks-with-examples-3283b554fc3b However, it's not clear to me a function such as zksnarkverify has been already implemented in ...
1
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2answers
137 views

Is data stored in string form in smart contracts publicly readable?

As a beginner, I wrote the contract below for learning purposes, aiming to create a "Safe Messaging System": pragma solidity ^0.4.24; contract SafeMessage { string message; string password; string ...
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1answer
249 views

Quorum privateFor visibility

Our current project requires that the recipients of a private transaction are unknown to the rest of the network. So my question is: is the privateFor field dropped before sending the transaction to ...
3
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1answer
57 views

How to use key derivation and 'coin selection' to increase privacy, like in Bitcoin?

In Bitcoin, you can have increased privacy by never re-using addresses. A single private key can generate many addresses if you are using a key derivation scheme. In Ethereum, instead of UTXOs you ...
1
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1answer
40 views

Is there a privacy token implementation in the works for Ethereum like Monero's Tari system?

With the recent announcement of being able to have privacy type tokens on the Monero blockchain. Is there a proposal on ethereum for something similar? The usecase of having a private ERC20 would be ...
1
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2answers
85 views

Is it possible to identify a smart contract if you know the byte code of it?

I am currently writing a master thesis about Ethereum. In the thesis, I develop a system to send data and do calculations with data on the ethereum blockchain with a smart contract. The system I am ...
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0answers
111 views

How to fund Ethereum address relatively anonymously? (breaking a link with an already established address)

I want to deploy smart contract. I just don't want people inspecting the code on Etherscan to see what crappy ICOs I've sent my ETH back in 2017... Some options coming to mind: use Shapeshift ...
3
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2answers
251 views

Is there a way to privately send ether?

Is there currently any way to privately send ether? If not, are there any plans in the future to implement any privacy features?
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2answers
443 views

How do I see the value of a string stored in a private variable? [duplicate]

I have read many times that sensitive data should never be stored in a transaction, but, specifically, how would the value of a state variable be read if marked private?
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0answers
40 views

Share private data and prevent data forwarding

Let's say A has some private medical records of patients and B is a pharmaceutical company who wants to view medical records from A to find out the effect of a particular drug on the patients (run a ...