Questions tagged [encryption]
Questions related to the encryption in Ethereum
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2answers
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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
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2answers
58 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
102 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
35 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
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1answer
79 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
32 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 ...
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1answer
83 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
275 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
61 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
29 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.
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0answers
82 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 ...
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3answers
249 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
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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
184 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
92 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
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1answer
53 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 ...
1
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1answer
54 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
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1answer
348 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
209 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
116 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 ...
0
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1answer
754 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
1k 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
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0answers
252 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
650 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
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1answer
36 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
180 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
675 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
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1answer
123 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
214 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
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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
849 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
107 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 ...
3
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0answers
400 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
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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
337 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
280 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 ...
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1answer
259 views
Why is Ethereum's key generation so much faster than GPG's?
Ethereum uses asymmetric public/private key pairs to generate its accounts. So does GPG.
GPG key generation takes ages and needs lots of time/entropy. Ethereum doesn't. Why the big difference?
3
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1answer
513 views
What is “a public key under ECIES”, and how to get it?
I read the JSONRPC document of Parity these days.
And I want to encrypt my message with the public key and private key of the accounts in Parity.
I found a JSONRPC in this web parity_encryptMessage
...
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1answer
789 views
How to use private key to encrypt message
I try to develop a storing image file dapp with Parity these days.
And I asked a question about private key some days ago. And Someone said that each account has a private key in Ethereum so that I ...
0
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1answer
213 views
Encryption of keystore, keys and cryptographic library usage locations
I understand that another question posted has mentioned that the keystore has
aes-128-ctr encryption: What is the strength of Mist wallet encryption?
Key Derivation Function uses scrypt (where the ...
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1answer
274 views
Smart Contracts and symmetric encryption
I am currently learning about smart contracts and there is a question I have.
I am trying to understand how smart contracts are executed. I read already different sources and I tinkered some ideas ...
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3answers
1k views
Contract function to decrypt a value after a certain date
I want to create a contract function that will decrypt and return a value given a password (or key) - but only after a certain date.
e.g. outside the blockchain I encrypt the value "ABCDEF" and store ...
