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Questions tagged [cryptography]

Discipline or techniques employed in protecting integrity or secrecy of electronic messages by converting them into unreadable (cipher text) form.

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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 ...
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1answer
41 views

HD wallet public to public key derivation and non-hardened keys

This question is about hierarchical deterministic wallets and the bip32 standard which, as I understand it, allows you to deterministically derive child private/public key pairs from a master seed ...
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1answer
13 views

Is it possible to provide some manual data to create private key for the ethereum account?

We were trying to provide some manual data to create the private key if I want to create a new ethereum account using this private key.
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1answer
47 views

Understanding Ethereum signatures

I would like to understand exactly which signatures are used in the Ethereum. Here https://bitcoin.stackexchange.com/questions/12554/why-the-signature-is-always-65-13232-bytes-long it says that there ...
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1answer
219 views

How can I get a mnemonic phrase from a private key?

I have a private key for my wallet and also a keystore for it. I want to use it in MEWConnect. Is there a way to get a mnemonic phrase from a private key?
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1answer
24 views

How to define 2048-bit integers on smart contracts?

As we know solidity supports only 256-bit big integers. But for crypto primitives (sometimes) we need bigger integers, e.g. 2048-bit. Question: how can we define 2048-bit integers on a smart contract ...
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15 views

Why is an ephemeral key used in creating a digital signature?

When creating the 'S' component of a digital signature, both the actual private key and an ephemeral private key are used. The reasoning I've read is to ensure that the sender’s actual private key ...
3
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1answer
55 views

Zero Knowledge v Multi Party Computation (MPC)

I am struggling with understanding the difference between the two. From what I am putting together, they have different adversarial models, MPC adds the condition of collusion between parties i.e. ...
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3answers
68 views

how to generate mnemonics from randombytes

I am able to get the randombytes using react-native-crypto-js const words = CryptoJS.lib.WordArray.random(32); Is that possible to generate mnemonics using random bytes.
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1answer
37 views

Is it possible to create one-time addresses, like in monero?

In http://src.getmonero.org/library/Zero-to-Monero-1-0-0.pdf, chapter "5.2 One-time addresses", there is description of how to create them. The problem is that Monero uses Ed25519 and Ethereum ...
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1answer
24 views

How to get two points (x, y) from an encoded pubkey?

this gives a valid address from two points; address(uint256(keccak256(abi.encodePacked(point[0], point[1]))) & 0x00FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF); but does that mean that if you are ...
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0answers
50 views

Ethereum geth node sync problem

I have to ethereum geth node runing as testnet syncmode=full on aws both running on same hardware and bandwidth why one is syncing very slow and other one is syncing fast? and if I will stop the ...
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1answer
28 views

Estimation of gas in web3js 0.20

Q:- While sending only Ether One wallet to another wallet(NO SMART CONTRACT), do we need to define the default gas limit and price? i.e. 21000 * 3 OR 21000 * 4 OR 21000 * 5 etc Or I've need to use ...
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1answer
131 views

Does Ethereum support pairing operations?

I need to build an application that uses bilinear pairing operations for generating signatures. If I send a message with its signature to Ethereum, can Ethereum verify this message? Does the EVM ...
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0answers
21 views

Using ECC Brainpool curves instead of Elliptic Curves

I am exploring the use of ECC Brainpool curves instead of elliptic curves for digital signatures in Ethereum. Is this part of the roadmap and/or anyone has experimented with the use of ECC Brainpool ...
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1answer
925 views

Why are Ethereum addresses hashes of public keys?

I understand how Ethereum addresses are generated. This thread has a great explanation: How are ethereum addresses generated? However, what this explanation is missing is why a hash is used. There ...
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2answers
42 views

Is data stored in string form in smart contracts publicly readable?

As a beginner, I wrote the contract below for learning purposes, aiming to create a "Safe Messaging System": pragma solidity ^0.4.24; contract SafeMessage { string message; string password; string ...
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1answer
24 views

discover if a binary data contains Ethereum address in it?

Is there a way to guess, with some level of probability , that a 20 byte array is an Ethereum address, besides doing a query against the current StateDB and its history ? I want to discover hidden ...
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1answer
111 views

Why are the last 20 bytes of the public key used as the address?

According to this post regarding how to derive the Ethereum address from a public key: Take the last 40 characters / 20 bytes of this public key (Keccak-256). Or, in other words, drop the first ...
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2answers
86 views

Can private keys change once created?

Can private keys change once the public key (address) is created?
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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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1answer
129 views

Solidity - Shuffle address[] Index

Hello World ! I'm trying to find a way to shuffle an array of addresses in Solidity ! Looking at Underscore / Lodash source code _.shuffle() points out a few things. _.shuffle([1, 2, 3, 4]); * // ...
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1answer
49 views

Masternode status monitoring website [closed]

I was working with the masternodes platform, i wanted to create the dashboard like masternodes.online provides. I have already setup my masternode and use its information within it. I want an api ...
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1answer
253 views

How can we verify BGLS aggregate signatures in Solidity?

BGLS [1] is an aggregate signature scheme by Boneh et al., that allows aggregation of signatures on n different messages from n different signers. What I want to achieve is to verify such signatures ...
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2answers
36 views

“Signing” a Smart Contract after it has been deployed

I've been tasked with writing a Smart Contract to create NFT/digital collectibles. For the most part, I'm using a standard ERC721 contract. I will be responsible for deploying the contract. Is there ...
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1answer
111 views

Store and retrieve audio files on blockchain using hashes and authenticity matching [closed]

I am looking to store and retrieve hashes of authentic audio files on the Ethereum blockchain with the purpose of checking authenticity of these audio files in the future with the hashes stored on the ...
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2answers
670 views

What are zkSNARKs? How do they work?

From my brief exposure to the concept, zkSNARKs seems to be a form of zero-knowledge cryptography. What can zkSNARKs bring to the table for Ethereum? I have looked at projects like this but still ...
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2answers
334 views

Creating a new wallet mobile application for newly created crypto currency

I am doing as a Intern in Apogee Tech Global in Bangalore on Blockchain for three months. My commitments is to learn solidity language, build smart contracts, learn Ethereum and Hyperledger. I learnt ...
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3answers
631 views

Can ZKSnarks be implemented on the Ethereum ecosystem?

Since Zcash seems to have it's ZKSnarks implementation finished (or almost at least). And versions of JPMorgan's Quorum had appeared with ZKsnarks implementations included see: https://www.coindesk....
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8answers
564 views

Would it be profitable enough to do a Master's degree in blockchain technologies (focused on ethereum above all)?

The end of my university studies is getting closer and closer. I'm sure I want to do a Masters degree, but I have some doubts. About a month ago my university released a Masters degree completely on ...
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1answer
32 views

Is there a privacy token implementation in the works for Ethereum like Monero's Tari system?

With the recent announcement of being able to have privacy type tokens on the Monero blockchain. Is there a proposal on ethereum for something similar? The usecase of having a private ERC20 would be ...
2
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0answers
44 views

cryptography algorithm used in ethereum [duplicate]

what algorithm does ethereum use to generate public and private key pair. If i have both the keys how can i verify the match of the key in solidity, and how much gas does it cost? is it an expensive ...
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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 ...
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1answer
199 views

Any understandable cryptography book/article/lecture to introduce to signatures, hashes, ECDSA etc..? [closed]

It's a long time I'm searching for cryptography lectures related to ethereum inside mechanisms, and everything I found has a high mathematical level. I'm an engineer, not a mathematics, so any article ...
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3answers
346 views

Will be a ring signature scheme possible to implement at Ethereum?

It's been quite a few days I'm wondering if a Ring Signature Scheme (like Monero (XMR) has) can be implemented on Ethereum blockchains. As far as I know, that will be so nice in order to increase ...
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0answers
135 views

How to send whisper messages to an ethereum address

I want to establish a communication channel between two ethereum addresses. I want to use whisper, however whisper requires the public key of the parties not the public address which is all I have, ...
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1answer
93 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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1answer
176 views

Why does a signed transaction include a “hash” field?

When signing a transaction using the go-ethereum library, the resulting object looks something like this: "tx": { "nonce": "0x7", "gasPrice": "0x77359400", "gas": "0x5208", ...
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2answers
42 views

Which is cryptographically harder (higher cost to break), sha256 or secp256k1?

Which has a higher computational cost, to find the private key associated with a signature, or, a pre-image of a sha256 hash?
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0answers
24 views

I to want introduce myself to learn new and advanced technologies like AI, blockchain [closed]

I have completed 2days blockchain executive program two weeks back. Course covers high-level concept on blockchain, ethereum I have around 12+ yrs of IT experience and worked on different tools and ...
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0answers
40 views

Generate Public Key

I use the command: > eth.getTransaction("0xac844bd1107761fec3abe2f55bf739f0e7cc6dd1cd169a60176bfb22 9826b5a8") Where the brackets contain the hash of the successful transaction. This is what I ...
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0answers
103 views

Ethereum public key recovery validation

I always thought that only the person(s) in possession of the private key to an address would be able to spend or change state for that account. But by using the recover technique rather than the ...
2
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1answer
43 views

Can I know an address on another blockchain that was generated with the same key as an ETH address?

Let's assume another blockchain (blockchain ATH) uses the same protocol to derive addresses from private keys as the one used by Ethereum. If I see an ETH address then I know for sure that the ...
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0answers
231 views

How to use Ethereum precompile bn256Pairing to check equality on symmetric groups?

The address 0x8 contains bn256Pairing pre-compiled contract on Byzantium release. I have the following questions : If I have G_1 = G_2, i.e., a symmetric pairing, is it possible to check e(a_1, b_1) ?...
2
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0answers
594 views

Ethereum Dapp Account Login Protocol with Metamask

I'm building an Ethereum dapp for users to use with Metamask. We're going to have an account management system and I was trying to follow this post on how to achieve a "password-less" account system ...
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1answer
180 views

Correct way to easily call function with web3j from deployed contract

I am trying to call a function from a modified ERC20 contract and I can't manage to make it work. I am doing this with web3j from Android. I can connect to Infura. The contract is already deployed on ...
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0answers
34 views

In ENS, what does the secret phrase encrypt?

The Ethereum Name Service uses a secret phrase to encrypt the bid. What is encrypted, to later be revealed during the reveal phase?
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1answer
651 views

Authentication using ethereum account

Trying to figure out a way to Authenticate users them having an ethereum account. New to ethereum and cryptography in general and my thought may not be adequate. In essence I am thinking to be able ...
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1answer
77 views

How to prevent tampering of contract call from the web?

I have a project where users will be calling my contract from the web. I want to ensure they call the contract with exactly the parameters I give them. My strategy was to hash the combo of parameters, ...
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1answer
409 views

Create hash in c# and validate in solidity

I'm trying to build an app that will call a contract from javascript. I want the contract to validate that the parameters weren't tampered with. In order to do that, my plan was to figure out the ...