Questions tagged [encryption]
Questions related to the encryption in Ethereum
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Encryption and Decryption when transmitting data
If I was sending data to a smart contract, do I need to encrypt it before transmitting and decrypt it in the smart contract? Or is this done automatically?
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2answers
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Blockchain Smart Contract EHR
I'm trying to do a miny EHR(Electronical Health Record) with Smart Contracts where I have a Pacient Contract.
The problem is that in solidity everything is public, even the private variables, so I ...
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1answer
46 views
How to get decrypted transaction data in quorum?
On Quorum_Node1 I am sending a transaction with privateFor: parameter as follows:
eth.sendTransaction({from: eth.accounts[0], to: "0xca84356...9a3d0ccf92b8e",
data: web3.toHex('sample message for ...
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0answers
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If nG and 2nG are known how to find generator point G [migrated]
if in a curve y2 mod p = x3+ 7 mod p ( ecdsa-secp256k1)
p=115792089237316195423570985008687907853269984665640564039457584007908834671663
G=...
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2answers
62 views
Offchain encryption in Ethereum dapp
Im wrting a dapp which holds / manages sensitive data which might need to be encrypted and decrypted and push again into chain.
I know it is not safe to encrypt data in smart contract,which is why Im ...
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0answers
54 views
Encryption with Ethereum Keys for all Clients (iOS,Android,Web)
I was trying to encrypt data with Ethereum Key pairs. So far, I have managed to encrypt and decrypt data with these keys using ECIES schema on eth-crypto. Eth-crypto is a package which is built on top ...
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2answers
23 views
Storing private data that will be decrypted by a smart contract
Another private data problem!
I would like to store some data in a Smart Contract, encrypted so nobody can see it upon some specific condition (time, or whatever).
For instance, after one year, this ...
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2answers
138 views
Encrypt data using public key
I have three data fields in a form which will return a string. I would like to hash the value of these three strings and store it in the blockchain. However the data in these three strings is ...
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1answer
193 views
How to encrypt a string with a smart-contract private-key and decrypt that offline
Say I want to make a smart contract that is able to save secret messages (strings). The messages should be stored only in encrypted form so no one can read them, but should be decrypt-able by a couple ...
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1answer
42 views
Is Data Stored on Ethereum encrypted or only RLP encoded?
Is Data Stored on Ethereum encrypted or only RLP encoded? If data is not encrypted, is there some way to secure and encrypt it using AES encryption algorithm in cipher block chaining (CBC) or XTS mode ...
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1answer
104 views
geth inter-node communication (devp2p/rlpx) encryption
I am currently analysing the encryption mechanisms used in geth.
Currently I have gathered the following information from the source code (https://github.com/ethereum/go-ethereum/blob/master/p2p/rlpx....
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1answer
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what encryption does myetherwallet use?
I am trying to use the encrypted ethereum private key created by myetherwallet within my application. Everytime I need to send money, I will input my password so that my application can decrypt it and ...
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1answer
117 views
Encryption with BIP39 specification secp256k1 keys?
We are making a system where users can share files with other people but nobody should be able to figure out that all these different files belongs to same user on blockchain.
these are the steps we ...
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0answers
413 views
How to use mnemonic to recovery my ethereum wallet
I use web3j to create my ethereum wallet.the Code just like down
import org.web3j.crypto.Bip39Wallet;
import org.web3j.crypto.Credentials;
import org.web3j.crypto.ECKeyPair;
import org.web3j.crypto....
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1answer
88 views
Understanding the UJO Smart Contract
I have trouble understanding the underlying mechanism for the UJO Music Portal, that helped Imogen Heap sell her album online. There is a smart contract that enables people to pay using ETH with ...
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1answer
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In ethereum if i submit any data is it stored in encrypted format? [closed]
Does Blockchain perform encryption/decryption of data?How and where is data stored in ethereum case.
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0answers
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Smart Contract - Storing 113+ byte buffer in solidity
So I am using the module (eth-ecies) in npm to perform encryption of a message offchain using the public key of my reciever, and in turn I get a 113+ byte buffer after the encryption is done. Now i ...
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3answers
301 views
RE-Encrypt file in IPFS
If I have an encrypted file in IPFS with a symmetric key that I share, can I after that decrypt and re-encrypt that file with a different key in order to revoke access?
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1answer
62 views
Potential attack
I have two computers, one of them is airgapped.
I had also two MEW private key, stored in the airgapped computer, I made a lot of transaction from the first private key to the second one.
...
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0answers
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key rocever from MEW locally thanks to a combo of addresses and signed transaction?
Hello I have used a private key to send the funds off line from and address to another using Myether wallet
All the signed transactions made, and the addressess where the coins ...
1
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1answer
191 views
Private key recovering from both addresses + signed transaction?
Hello I have a problem.
I have two computers, one of them is airgapped
I have downloaded and runned Myetherwallet locally on an airgapped computer.
On the other computer I made the on line ...
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1answer
1k views
Is it possible to derive public key from ETH address?
Goal (not asking XY question):
send ETH to an address
web3.js script monitoring it and acting upon transaction
if msg.value > 0.1 ether then...
...encrypt a file with the public key of the msg....
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1answer
120 views
How to decrypt using Public Key
Can anyone decrypts cipher-text using Public Key? as I know we can only decrypt using private key, but in this RLPx documentation what this line means?
Receiver receives the initiator handshake and ...
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1answer
59 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?
...
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2answers
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When creating an account with the Mist wallet, is the password a key for encrypting my wallet file or is it for something else?
In the book "Introducing Ethereum and Solidity", there is a paragraph that says:
"There is no Forgot Password functionality in the Ethereum network. That’s
because your password is only for this ...
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1answer
64 views
Could my private key could be reconstructed from just the ciphertext, salt and my password
Lets assume hypothetically that I have these all written down on paper somewhere. In comparison to the keystore, which I consider a JSON file that's too long, can I theoretically disregard all other ...
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1answer
391 views
A bit confused. How do I send ether using Web3j to an address (Android)
EDIT: I am using android platform
I think I'm a bit confused conceptually. I would appreciate it if someone could answer these few questions for me as I'm trying to make an app so that I can be ...
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3answers
2k views
How to encrypt a message using only the public key from web3.eth.sign?
I retrieve the public key of a users account using Web3 as follows:
web3.eth.sign(web3.eth.accounts[0], web3.sha3('test'), function (err, signature) {
var sigtest = signature
...
0
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1answer
226 views
Using smart contract to verify computation on encrypted data
I’m working on a project where all data is stored encrypted on a blockchain. There are some off-chain compute nodes that have the key to decrypt the data and perform some computation and return ...
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0answers
135 views
Can you use a smart contract to generate a symmetric key?
Let's say that I want to generate a key such that a user can use it and at the same time save the hashed key on the blockchain. My idea was to use a smart contract that could implement the Diffie-...
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2answers
2k views
What the difference between Bitcoin and Ethereum private/public keys and address?
I am trying to find a library for creating Ethereum wallets in a web environment (PHP, JS). I found Keytheremjs lib, but if use it in a browser, this tool is very slow. But I found a lot of simple PHP ...
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1answer
875 views
How do you hide data on the blockchain? [duplicate]
I am designing a system where some data needs to be hidden and the idea is to store it in an encrypted file. How can you allow nodes to interact with it through a smart contract without revealing the ...
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2answers
2k views
Ethereum wallet v3 format
Can someone explain what exactly Ethereum wallet file (v3) contains, and how it works. How exactly public-private key pair is encrypted. Why two encryption algorithms are mentioned in the file (aes-...
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0answers
280 views
OpenSSL error message when decrypting Ethereum encrypted private key
I'm trying to help a friend recover his password for an older format ethereum encrypted private key (EPK). My friend thinks he knows the password. My plan has been to use his best guess at the ...
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0answers
724 views
Smart Contract Encryption and Decryption so that only parties involved can read the content of Contract [duplicate]
I am trying to make a document sharing app after signing the NDA between 2 parties.
My Smart contract saves the address of involved parties as Sender(Party1 who makes the NDA) and recipient(Party2 ...
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1answer
41 views
Make a variable not-visible
I am trying to create a smart contract where people can send some data as string. This data must be not-visible/not-readable by anyone until a certain date(let's say one month from now)
Have I to set ...
0
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1answer
194 views
Access control of the external resource sold using a DApp?
I'm trying to create a smart contract in Solidity that the accounts can access the digital content only after paid some tokens.
For example, assuming Account 1 is a buyer and Account 2 is a seller. ...
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2answers
2k views
Storing and passing encrypted data to another owner
I've been thinking about this situation for quite a while and I wonder if there is a way to solve this on the public Ethereum blockchain.
User A stores some data on the blockchain, encrypted in some ...
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1answer
748 views
How to generate signature & validate signature offline w/o using web3
I just need a simple way to sign a message offline, preferably using Python or JavaScript.
I don't want to have to sign in using Web3. I just want my private key to be used from a variable in the code....
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1answer
129 views
Does the private and public keys determine each other uniquely?
I wonder whether for each private/public key there correspond a unique public/private key?
Of course, it must be computationally infeasible to compute the private key from the public key, but does ...
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0answers
222 views
Homomorphic Secret Sharing
Speaking of Ethereum blockchain, Is it possible to perform homomorphic secret sharing algorithmic calculations like SSS/pVSS/VSS on-chain? or should this be calculations performed off-chain
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0answers
135 views
Is there a strategy for keeping data “private” and then releasing it programmatically [duplicate]
I'd like to do the following:
Have a smart contract with an IPFS link as part of the contract whose contents are in some way "private" or otherwise inaccessible
At exactly one point in time, release ...
3
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1answer
873 views
Brute-forcing private keys
In this post by an Ethereum engineer taken from the Ethereum wiki about brute-forcing private keys, he writes:
"Public keys are sized so that, absent a breakthrough in solving the
discrete ...
2
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1answer
108 views
How do existing applications on the Ethereum blockchain enforce confidentiality of data?
How do current applications on the Ethereum blockchain enforce confidentiality of data?
I know that the state of a contract is visible to any node on the network. Does this imply that there are no ...
3
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1answer
67 views
Can contracts act as decryption programs? [duplicate]
I am trying to make a contract that receives an encrypted signed transaction and stores it for later use. This transaction can only be decrypted if the specified wallet sends a transaction to this ...
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0answers
437 views
“Invalid DER format public key” error trying to use bitcore-ecies for encryption with Ethereum keys
I started this blog for generation of the keys. Which I'm able to follow successfully. My generated Private, public key and the address is mentioned in the testIdentity variable in the code below.
...
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4answers
2k views
Cryptography in a smart contract
is there a way using public key cryptography (asymmetric cryptography) in a smart contract. The idea is to:
1) Encrypt some text and publish it on the block chain as a transaction.
function ...
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2answers
382 views
How does Quorum prevent double spending when states are encrypted?
My understanding of Quorum is that private contracts have encrypted states hence I am confused as to how they reach consensus and prevent double spending. If each state is encrypted how can the nodes ...
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3answers
292 views
How to cryptographically challenge a public/private address key pair?
I know that in the Ethereum protocol, users submit transaction by cryptographically 'signing' their transactions using their private key to prove to the miners that they do own that key but without ...
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1answer
1k views
Python ECDSA Public Key Recovery
How do you recover the EC public key from a VRS style signature in python?
I am trying to setup some encryption between two parties via ECIES, but I first wanted to obtain the public key via recovery ...
