Questions tagged [encryption]

Questions related to the encryption in Ethereum

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27
votes
2answers
9k views

How to encrypt a message with the public-key of an Ethereum address

I am writing some code in nodejs/browser. I have successfully created ethereum-addresses with the secp256k1-library. I was also able to sign and verify messages. Now I want to encrypt/decrypt a ...
23
votes
1answer
12k views

Ethereum ecrecover signature verification and encryption

The question of signing and verifying signatures with Solidity has been asked in these questions, both of which I have tried to study: How can I sign a piece of data with the private key of an ...
22
votes
1answer
2k views

What are effective techniques to encrypt/decrypt data stored in a smart contract?

Rather than sending and storing plain text in a smart contract, the use case objective is to encrypt first and then subsequently access the data and decrypt at the point of use. What is the most ...
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 ...
11
votes
1answer
7k views

How to generate a keystore (UTC) file from the raw private key?

If I have the plaintext private key, -how- can I generate a geth-compatible keystore file using Node.js? I think I need to encrypt it using the scrypt algorithm by supplying a password, but I don't ...
10
votes
3answers
586 views

Are communications encrypted?

I'd like to know whether the messages delivered to the ethereum network by my wallet are encrypted such that any identifying information about the wallet is inaccessible to the ISP? in other words, ...
10
votes
2answers
2k views

Using Ethereum for data encryption

I'm trying to find a way to use an ethereum address/solidity/web3 for text encryption , but i'm not even sure it's possible to get the public key from the address(hash of the pubkey) using secp256k1 ...
9
votes
1answer
4k views

What's a recommended way to pass secret in Solidity?

Hi I'm an Ethereum noob just trying something out. I have a quick question for the community here about passing secrets in Solidity. Since, we can only control who can change state variables in ...
7
votes
1answer
3k views

Current methods to send encrypted messages from contracts

I am trying to understand if there currently exists a method to send a message from a contract to another contract or a private address? What would the Solidity code for this look like? Perhaps events ...
7
votes
2answers
847 views

Does Ethereum offer encrypted peer to peer communication applications?

I am wondering if Ethereum can be used for encrypted peer to peer communication like delivering encrypted short messages or encrypted data in bulk between two or multiple parties. Are there any ...
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 ...
6
votes
2answers
2k views

Can smart contracts compute on encrypted data?

There's a ton of super technical articles out there published about this, but I cannot understand them because I don't have a PHD in cryptography. So then, put simply, can I or can I not have smart ...
6
votes
2answers
4k views

Encrypted data in the block chain

I thinking of developing some kind of application in which I need to have some kind of public key cryptography done by the smart contract. The sender sends some data to the smart contract encrypyted ...
6
votes
1answer
1k views

What underlying protocols are used to send packets between nodes, and how are messages encrypted?

In Ethereum, when we make transactions, which underlying protocol is used to send the packages over the network? And another question, are those messages are encrypted or not? TCP, UDP, others? All? ...
6
votes
2answers
1k views

What algorithm is used to encrypt a private key?

In my understanding, private keys are encrypted with some symmetric algorithm, so you can't access them without passphrase. What is it called?
5
votes
2answers
618 views

Make data from smartcontracts / events only visible for certain address/users

I Have an use case where i need : 1- My data not to be visible to the public. 2- To be able to revoke my clients/users rights to view said data from my smart contract. As anyone done that before ? ...
5
votes
1answer
256 views

Unlinkability between transactions to a smart contract

I am trying to develop an application using Ethereum and it needs to have transactions which are not linkable. I read an article by Vitalik Buterin, which speaks about it. He speaks about something ...
5
votes
1answer
540 views

Current state of zero knowledge proofs?

Are there any current proof of concepts or implementations of zero knowledge proofs in the context of smart contracts? If not how long until we can store private data on a public blockchain?
5
votes
1answer
750 views

Size of Ethereum transaction and its signature component? [duplicate]

A couple of questions: What is the average size of an Ethereum transaction in bytes (considering say a basic value transfer case). Also, what is the size in bytes of the signature component of the ...
4
votes
4answers
732 views

“SSO-style” Login into app with web3.eth.accounts[0]

On top of the data exchanged through the Ethereum network, my app stores some extra user data in a classic DB (E.g. thumbnails, display preferences, newsletter management etc.). Doing that has led ...
4
votes
1answer
529 views

Unknown Keystore / Encrypted Wallet Format

Have a user with a keyfile format that I don't recognize and MEW can't decrypt (obviously). Anyone have any insight on where this came from or what the encryption mechanism is? Sensitive info has been ...
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 ...
4
votes
1answer
623 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 ...
4
votes
2answers
127 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 ...
4
votes
1answer
261 views

Does a greater number of hashing rounds in aes-128-ctr scrypt key generation mean stronger encryption?

Consider the following Ethereum account I created at MyEtherWallet: { version: 3, id: '4447b704-e28c-4e93-8b1d-32f519b46692', address: '115312fc0ab77a0fb15a66baf51f58baefcee1dd', Crypto: { ...
4
votes
1answer
547 views

Is there a BIP38 equivalent for Ethereum private keys?

What is the best practice to encrypt an Ethereum private key? For example, Bitcoin has BIP38.
3
votes
1answer
131 views

If two keystore files have the same password, can it be figured out?

If two different keystore files have the same password, can it be figured out? Suppose I publish to the internet two keystore files corresponding to two different addresses. The files have the same ...
3
votes
3answers
407 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?
3
votes
2answers
240 views

Securely send symmetrically encrypted data to contract?

Hey there I was wondering what the best technique would be for sending encrypted data to a contract, which can later be decrypted, either by the initial user, or by the contract itself, but not anyone ...
3
votes
1answer
725 views

Hiding variables in Solidity [duplicate]

What is the best way to encrypt and decrypt a variable in Solidity so only the msg.sender and contract can see that variable?
3
votes
1answer
149 views

How to create modifers for permissioned access

I have a citizenship persona contract which acts as a personal identity file which is under the control of the user. Personas can make other personas in the system into trustees or allies. As part of ...
3
votes
1answer
222 views

Ethereum Wallet 0.5.2 >Confirm Encryption Loss> message when extracting zipped folder

Trying to download Ethereum Wallet 0.5.2 mist off github and I after downloading I click through folders and get the following message: This occurs when I attempt to extract the compressed folders. ...
3
votes
1answer
910 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 ...
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
1answer
632 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....
3
votes
0answers
500 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. ...
3
votes
0answers
2k views

How to brute force decrypt wallet password ?

I have forgot my wallet password, but have an idea what it could be. I need to put a script together to try a long list of possible password. What is the command to use for that, if I am to put it ...
3
votes
0answers
153 views

How to encrypt messages to an account owner with the Ethereum public key? [duplicate]

As I understand it, an Ethereum account is a public/private key pair. Is it possible to encrypt a message with the public key (how?) that only the account holder can decrypt it with his private key? ...
2
votes
2answers
305 views

Mist password not working. Is there a way to open a new account?

I have a mac. How do I delete mist and re-download it + blockchain so I can start fresh? My original password is not working (only 1 eth in it so not worried about loss). If it needs to be deleted ...
2
votes
1answer
79 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 { ...
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 ...
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 ...
2
votes
1answer
26 views

Algorithm used for symmetric key encryption by quorum

What are the symmetric key encryption techniques used by the enclave in quorum to encrypt the payload? The documentation of quorum mentions that the enclave uses a symmetric key to encrypt the payload ...
2
votes
1answer
155 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....
2
votes
1answer
510 views

How to decrypt an ECIES encrypted message using a geth account and JSON-RPC protocol?

A geth node is managing an Ethereum account, having the control over its private key at keystore folder. I guess to keep it safe, best practices are letting geth by its own perform all operations that ...
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 ...
2
votes
2answers
126 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 ...
2
votes
0answers
382 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
2answers
3k 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-...
1
vote
1answer
208 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 ...