Questions tagged [encryption]

Questions related to the encryption in Ethereum

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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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173 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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304 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?
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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
918 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 ...
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332 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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85 views

as IBM openblockchain said data are encrypted in that, Is data in Ethereum are encrypted?

Data refers to transactions,contract code functions,arguments passed to smart contract functions.
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533 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
277 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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1answer
96 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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2answers
498 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
374 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
289 views

Parity encryption password help

{ "id":"eca798d8-8e68-a096-a35f-174133f86e43", "version":3, "crypto": { "cipher":"aes-128-ctr", "cipherparams": { "iv":"45092c0a2032250e66a9d0bd2a33acaa" }, "ciphertext":"...
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4answers
2k views

Decryption in a smart contract

I have a key pair: The data is encrypted off-chain: and it is saved into the following smart contract: contract Foo { string data; } Can I decrypt stored data on-chain, assuming I provide a ...
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1answer
191 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
150 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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874 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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239 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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151 views

Encrypted accounts backup and restore from 12 word seed

In my wallet I used ethereumjs-accounts library to generate and manage accounts. It allows to export and import accounts by json string or zip file. My goal is to add to export/import functionality 12-...
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1answer
1k views

How to create a contract with private data accessible to a particular user?

I want to create a contract that stores encrypted data that is accessible only a selected user on the blockchain. A ideal scenario would be to encrypt the data using the user's public key, such that ...
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0answers
20 views

Is it secure to call function without any encryption? [duplicate]

I mean, if I have a contract with function like: string current_password; function set_password(string password, string new_password) { if (password == current_password) { ...
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2answers
700 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
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....
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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 ...
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1answer
35 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 ...
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1answer
172 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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53 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 ...
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2answers
35 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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63 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
54 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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56 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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65 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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1answer
89 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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1answer
231 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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763 views

Crypto package not resolving

I have the same problem as in 'How to apply pyethrecover.py on v3 .json/transfor v3 .json to .v1' referenced here, but in trying the answer's code, I am finding that the Crypto package is not being ...
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36 views

How can I encrypt a file using an ethereum public address and decrypt it with the private address?

The expected outcome is very simple: Users will send their ERC20s to a smart contract. Depending on the amount, each user will get a file specifically created for them. I want to distribute that ...
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23 views

Data encryption

Since all data on the Blockchain is public. Presume I have multiple users submitting data which I want to hide, is there a way I can encrypt that data on the Blockchain ? Or do I have to encrypt off-...
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1answer
51 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 ...
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1answer
36 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 ...
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2answers
55 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?
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210 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 ...
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152 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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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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692 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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307 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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200 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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1answer
42 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 ...
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1answer
933 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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237 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 ...