Questions tagged [encryption]
Questions related to the encryption in Ethereum
96
questions
0
votes
1answer
40 views
Asymmetric encryption with master Key
Is there any way i can derive private and public keypairs from a Master Key? The Master Key should be able to decrypt every encryption made with the generated Keypairs.
to explain a bit further i ...
0
votes
1answer
24 views
How to store and encrypt Keys?
I am developing chrome extension like metamask for the private Chain. I have generated the keys and using localStorage to store the Keys. But I am not sure whether I am going correct or not for ...
0
votes
1answer
34 views
Storing encrypted data and decrypt on-chain
The idea was to store the encrypted number of tokens,and when user was sending his private key, smart-contract would decrypt the data and perform an action of sending tokens to someone else. The catch ...
2
votes
1answer
71 views
Decrypt message on-chain
I want to store some data in smart contract and then decrypt it on chain. Pseudocode:
contract EncryptedData {
bytes data;
string public decryptedData;
constructor(bytes data_) public {
...
4
votes
2answers
114 views
How to encrypt a file with multiple public address?
Can I encrypt a file with multiple public address such that each of them can decrypt the file using their private keys?
Thus achieving a system to securely store file on IPFS which can be accessed by ...
0
votes
1answer
29 views
Assymetric encryption with only address
I would like to send an encrypted message to an address, without knowing their public key.
If I understand ECIES correctly, in order to send an encrypted ECIES message to a party, say Bob, I need to ...
0
votes
2answers
44 views
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?
0
votes
2answers
107 views
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 ...
0
votes
1answer
117 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 ...
2
votes
2answers
112 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 ...
0
votes
0answers
125 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 ...
0
votes
2answers
29 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 ...
0
votes
2answers
391 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 ...
1
vote
1answer
334 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 ...
0
votes
1answer
56 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 ...
2
votes
1answer
146 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....
0
votes
1answer
41 views
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 ...
1
vote
1answer
189 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 ...
3
votes
1answer
594 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....
1
vote
1answer
125 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 ...
0
votes
1answer
52 views
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.
0
votes
0answers
114 views
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 ...
3
votes
3answers
386 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?
0
votes
1answer
64 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.
...
1
vote
1answer
206 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 ...
0
votes
1answer
2k 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....
1
vote
1answer
141 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 ...
0
votes
1answer
76 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?
...
0
votes
2answers
28 views
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 ...
1
vote
1answer
82 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 ...
0
votes
2answers
528 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 ...
2
votes
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
votes
1answer
261 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 ...
0
votes
0answers
161 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-...
13
votes
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 ...
0
votes
1answer
1k 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 ...
1
vote
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-...
2
votes
0answers
363 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 ...
1
vote
0answers
794 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 ...
0
votes
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
votes
1answer
209 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. ...
7
votes
3answers
3k 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 ...
0
votes
1answer
822 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....
1
vote
1answer
153 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 ...
1
vote
0answers
231 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
3
votes
1answer
899 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
votes
1answer
114 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
votes
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 ...
3
votes
0answers
488 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.
...
4
votes
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 ...
