Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [encryption]

Questions related to the encryption in Ethereum

0
votes
2answers
21 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
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 ...
1
vote
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 ...
0
votes
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
votes
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....
0
votes
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 ...
1
vote
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 ...
1
vote
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....
1
vote
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 ...
0
votes
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.
0
votes
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 ...
3
votes
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?
0
votes
1answer
53 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. ...
0
votes
0answers
18 views

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
vote
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 ...
0
votes
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....
1
vote
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
votes
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? ...
0
votes
2answers
20 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
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
votes
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 ...
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
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 ...
0
votes
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-...
12
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
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 ...
1
vote
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
votes
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 ...
1
vote
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
votes
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
votes
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. ...
6
votes
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 ...
0
votes
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
vote
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 ...
1
vote
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
0
votes
0answers
123 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
votes
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
votes
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
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
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
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 ...
1
vote
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 ...
1
vote
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 ...
1
vote
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 ...
1
vote
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
votes
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 ...
1
vote
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
votes
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 ...
1
vote
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 ...
2
votes
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 ...