Questions tagged [signature]

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113 views

Correct way to verify address server-side with Web3 [duplicate]

I'm trying to use web3 1.0 to authenticate users on a web server. Instead of having unauthenticated users submit a username and password, I want them to send their address (public key). I'll respond ...
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2answers
520 views

Why doesn't my verification of a signed message signature work in PHP?

I am attempting to verify a signed message in PHP. To be clear, I am not looking to interface with JSON-RPC or any external service, which I both a) know works and b) successfully verifies the ...
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1answer
24 views

Do you spend gas to sign a message and send it to another client?

Let's say that I want to send the hash of a key to an entity and I want the entity to be sure that the hash could have come only from me. It is possible to create a message with the hash of the key ...
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0answers
274 views

Does Geth have more transaction signers than EIP155Signer, FrontierSigner, and HomesteadSigner?

I'm trying to write code (in Scala) to verify transactions on the main net and I've go it to where it works on about 50% of transactions. The steps I'm following are: Download the transaction using ...
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1answer
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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2answers
724 views

How can I use geth's ecRecover to verify a signed message from TREZOR?

I cannot get this to work. I understand from this that TREZOR adds the magic message and a hexadecimal message length (as opposed to ASCII length) of the message before signing. Is it just not ...
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2answers
171 views

Encrypted data and digital signatures in the blockchain?

Let's say that Alice publishes some data on the blokchain encrypted with Bob's public key. Bob then decrypts the data. Later Bob wants to prove that he is the owner of that data, that is he wants to ...
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1answer
79 views

When verifying that a cryptographic signature was produced by an ethereum address, how can I verify the validity of the data which was signed?

I'm attempting to play around with signature verification in solidity through the use of ecrecover and have gotten to the point of being able to verify the address which was used to sign a particular ...
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0answers
70 views

Can I use a Bitcoin client to sign a message with an Ethereum address?

If an Ethereum address is a point on the Bitcoin EC, then one can use the private key that matches that address to sign a message using bitcoin software. I'd like someone to prove they have the ...
1
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1answer
709 views

How do you find the public key used to sign a transaction?

I'm trying to figure out how you find the public key used to sign a transaction from v, r, and s. Before someone says so, this isn't a duplicate of Get public key of any ethereum account. That ...
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1answer
307 views

Gas Requirement for Ethereum Message Signing

Is Gas required to sign a message using ethereum?
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2answers
265 views

Tx.origin and msg.sender when sending signed Raw transaction

A client with address A signs a raw transaction, and leaves it all ready to be sent, gives it to the server with address B, which later will send it with sendSignedTransaction(...). What will be the ...
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3answers
4k views

Signing message: Provided address is invalid, the capitalization checksum test failed, or its an indrect IBAN address which can't be converted

Provided address is invalid, the capitalization checksum test failed, or its an indrect IBAN address which can't be converted is not a dupe, this is about signing messages My code: const ...
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3answers
17k views

How to properly create a raw transaction and sign it using web3 in browser

I want to create and sign a transaction in browser using web3. In order to create a raw transaction, I think I have to do something like this (hopefully you can fill the gaps of my knowledge) var pk =...
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1answer
116 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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2answers
463 views

How to make function signature? ERC223 ContractReceiver

Hi what does these lines mean? function tokenFallback(address _from, uint _value, bytes _data) { ... uint32 u = uint32(_data[3]) + (uint32(_data[2]) << 8) + (uint32(_data[1]) << ...
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2answers
718 views

Deriving the v value from an ECDSA signature without web3j

I am currently signing with a the ECDSASignature spec in java however I noticed that getting a v value from the signature is a custom spec for ethereum. My code: public static void main(String[] ...
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0answers
147 views

Convert an hexadecimal string to bytes in pure Solidity

I am using Oraclize to recover a signature from a website. When I have it, I have to check if the address who signed it is correct. To do that, I would use ECRecovery from Zeppelin. The signature ...
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1answer
401 views

Implementing EIP 155 for Signing Party

EIP-155 states: If block.number >= FORK_BLKNUM and v = CHAIN_ID * 2 + 35 or v = CHAIN_ID * 2 + 36, then when computing the hash of a transaction for purposes of signing or recovering, instead ...
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0answers
369 views

keccak256 returns 0x000000000000000

I am using the keccak256 hashing algo to retrieve a message for a signature however I am getting the return value above. Here is the code: function adminAuthorizedSwap(string price, string quantity, ...
2
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2answers
498 views

how to use personal_sign

https://github.com/ethereum/go-ethereum/wiki/Management-APIs {"method": "personal_sign", "params": [message, account, password]} The param message is a hex string, how can I generate it from a tx? ...
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1answer
428 views

How do I set the Ledger Nano S to display the recipient's full address?

Presently the Ledger Nano S is showing only the first few first and last digits, with the middle truncated. Why does it truncate the middle of the address? How do we display the entire address?
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1answer
235 views

What is the best type to store a signature on chain?

I'm signing a hash and getting a string with 130 bytes. What is the best way to store this signature later in my smart contract? Should I just go ahead and split it into r,s, and v and store it in ...
4
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1answer
334 views

Verifying Bicoin signed message in Ethereum smart contract

I'd like to explore the option to verify the messages that have been signed in Bitcoin wallets in Ethereum smart contracts. Ethereum smart contract is given a list of Bitcoin addresses Ethereum smart ...
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0answers
336 views

Can the precompiles in Byzantium for pairings be used for implementation of BLS verification?

I am looking into implementing some operations for the BLS signature scheme in Solidity, using the new precompiled contracts for pairing operations released with Byzantium. In BLS verification, to ...
2
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1answer
391 views

How do I split a signature into v, r, and s parts in python?

I've got a signature, as a python bytes object, and want to split it into the components v, r, and s. I understand the details of what needs to be done, by reading: What's the best way to ...
3
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3answers
249 views

Sign a raw TX without a library?

I am looking for a way to sign a transaction manually by having the necessary input without using any libraries. I haven't found how the signing process exactly works anywhere hence why I am asking ...
4
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1answer
403 views

Can a message hash be recovered from a signature?

A message can be signed and its signing public key recovered given the signature and message hash... signature = web3.personal.sign(<account>,<message hash>) pubKey = web3.personal....
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1answer
589 views

Signature in Ethereum: Are all a transaction fields signed?

Assume a transaction is tx. My question is that Question 1: Does a sender sign all fields in a transaction and put the signature in the transaction?, so does it send to the network? Question 2: ...
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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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1answer
102 views

Verify multiple state channel signatures in one transaction

What are some ways to verify multiple state channel signatures (using ECverify) in a single transaction?
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0answers
132 views

Can not retrieve Ethereum address form transaction signature on Python

I'm trying to retrieve the ethereum address from the transaction signature. I have got the following transaction: { blockHash: "0x82388a80a654586ec646115ae63a664e594e0e34dd6fb20dcf078d9495788578", ...
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1answer
430 views

Signatures differ in web3js and web3j

I'm using web3J version 3.0.0-alpha4 and hit following problem. When I sign the same raw message (it's simply string like "TEST" for now) I get different signatures using web3js i web3j. The signature ...
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2answers
455 views

Ecrecover: does passing the hash and checking it adds any security?

I have seen quite a few examples where both the data and the hash of the data is passed. The signature is verified using ecrecover which is fine. The passed hash is also verified against the ...
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0answers
54 views

Similar to currency-abstraction, could there be cryptography-abstraction (free market for digital signatures on a single state)?

Currency-abstraction for mining rewards was planned for Serenity, and so on, and so is out there as an idea. I thought about "signature-abstraction", so that different digital signatures could compete ...
4
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1answer
2k views

Verifying personal.sign signature with pyethereum

I'm trying to verify a signed message from Metamask with pyethereum. I can not seem to recover the correct address from the signature. Lack of documentation isn't helping matters. On the client ...
1
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1answer
408 views

Sign a transaction hash using JavaScript

Which JavaScript library should I use to sign a transaction hash? I don’t want to sign a transaction object. I simply want to sign the hash so I'll have a signature, not a signed transaction object.
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0answers
238 views

Send signed transaction hash to the network

The Parity native signing app takes the hash of a transaction and signs this has with a private key, derived from a seed phrase. Below is the corresponding code from signer.js: let account = getState(...
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0answers
32 views

Verify Signature in JS Console [duplicate]

In the geth console: eth.sign(eth.accounts[0],web3.sha3('yesyesyall')) Returns: "...
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0answers
234 views

Can contracts trade on etherdelta?

I was told that contracts can not trade on etherdelta because they can not sign transactions, could someone clarify?
3
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1answer
68 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 ...
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2answers
40 views

What information can be publicly read from a signature?

Without knowing anything else than the signature itself, what information if any can be publicly read from the signature?
3
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2answers
1k views

Sign without “\x19Ethereum Signed Message” prefix

I understood that web3.eth.sign(...) will add “\x19Ethereum Signed Message” prefix to a message and hash with keccak256. Is there anyway to remove the prefix before signing? Or any library I can use ...
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4answers
1k views

When is a transaction signature checked in a contract?

In the Solidity tutorial and examples here, I don't see any signature checking. In particular, in the contracts provided there, they don't check whether the sender of a message is actually the person ...
1
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1answer
387 views

How do you multi-sign a piece of data with multiple keys?

I'm aware how one can sign a message with a single key using web3.eth.sign or helpeth. How can multiple keys sign the same message? (preferably with an example using web3)
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2answers
2k views

Is it possible to sign a message in Solidity?

I am trying to sign and verify a signature in Solidity. I understood that it is possible to verify a signature using ecrecover. However, I am not able to find any useful information on signing.
2
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1answer
707 views

How public key is recovered for signature verification?

I see address everywhere in ethereum but not public key, and I understood that address is Keccak-256 of pubkey, and I do not think it is possible to derive pubkey from address. So, my question is ...
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2answers
649 views

What if two ether functions have the same signature?

It should not be hard to find collision. There is only 4 294 967 296 possible signatures.
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1answer
4k views

Can I web3.eth.sign with private key

I want to use web3.eth.sign to create a signature that will be stored in blockchain and verified later by a contract (with ecrecover). I'd like to use as few libraries as possible. Web3 docs specify ...
4
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1answer
1k views

Mobile app to sign tx of another app (similar to Metamask in browser)?

I am looking at an architecture of a native (this is given!) iOS app which I want to integrate with an external wallet. For web apps we have the beloved Metamask which takes care of signing txs. Since ...