P2PoW | P2P Delegated Proof of Work solution | Cryptography library
kandi X-RAY | P2PoW Summary
kandi X-RAY | P2PoW Summary
This project has the ability to make Nano instantaneous for any type of low computing device by delegating PoW to Workers on a P2P network, requiring no central servers / coordinators. P2PoW is the rebranding of Delegated PoW, created by me, Anarkrypto, in October 2019 and winner of NanoJam - first hackaton involving the Nano cryptocurrency. P2PoW rewards "workers nodes" providing computing resources to Nano users in exchange for a small fee. Using Nano's DAG technology, it was possible to create a safe mechanism where neither party can be dishonest. This eliminates any need for central coordinator / authority in the process. The only way a user can have their transaction validated by Worker is to attach an extra transaction block as a reward after their transactions. The only way for a Worker to receive his reward is by completing PoW and broadcasting the user's transaction first to be able to validate his reward block. Read more in this Medium article.
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P2PoW Key Features
P2PoW Examples and Code Snippets
Trending Discussions on Cryptography
I'm trying to achieve the exact opposite of this here where I need to sign a payload in Python using ECDSA and be able to verify the signature in JS.
Here is my attempt, but I'm pretty sure I'm missing something with data transformation on either or both ends.
(Key types are the same as in the answer provided to the question above)
I've tried some other variations but nothing worked so far.
(The verification on JS returns False)
ANSWERAnswered 2022-Apr-10 at 18:16
The main problem is that both codes use different signature formats:
sign_payload() in the Python code generates an ECDSA signature in ASN.1/DER format. The WebCrypto API on the other hand can only handle the IEEE P1363 format.
Since the Python Cryptography library is much more convenient than the low level WebCrypto API it makes sense to do the conversion in Python code.
The following Python code is based on your code, but additionally performs the transformation into the IEEE P1363 format at the end:
In .NET 6 code from How can I SHA512 a string in C#?...
ANSWERAnswered 2021-Nov-27 at 16:16
In my case I was using RNGCryptoServiceProvider in .NET 5 but when I updated to .NET 6 I got the same warning. After reading about it in this issue I changed my code from this:
Based on the example provided here on how to establish a shared secret and derived key between JS (Crypto-JS) and Python, I can end up with the same shared secret and derived key on both ends.
However, when I try to encrypt as below, I cannot find a way to properly decrypt from Python. My understanding is that probably I am messing with the padding or salts and hashes....
ANSWERAnswered 2022-Mar-28 at 11:29
The issue is that the key is not passed correctly in the CryptoJS code.
The posted Python code generates
LefjQ2pEXmiy/nNZvEJ43i8hJuaAnzbA1Cbn1hOuAgA= as Base64-encoded key. This must be imported in the CryptoJS code using the Base64 encoder:
Everytime I publish my Blazor Server-project to my website domain, and opening the website, this exception occurs, and there's little to no help Googling it:
And it says
AppState.cs: line 21, so here's the codeline for it:
This exception is not happening under debugging localhost. When I delete localStorage from the browser on my website, and refreshing, then everything works. But I don't want my customers having this exception and having to tell them to delete the localstorage everytime I'm publishing.
My Program.cs if necessary:...
ANSWERAnswered 2022-Mar-16 at 13:16
Try to set
Load User Profile to true in your
IIS app pool in the advanced settings.
see this answer, I hope that will help you!
ANSWERAnswered 2021-Dec-13 at 14:56
The blind-signature library used in the NodeJS code for blind signing implements the process described here:
BlindSignature.blind()generates the SHA256 hash of the message and determines the blind message m' = m * re mod N.
BlindSignature.sign()calculates the blind signature s' = (m')d mod N.
BlindSignature.unblind()determines the unblind signature s = s' * r-1 mod N.
BlindSignature.verify()decrypts the unblind signature (se) and compares the result with the hashed message. If both are the same, the verification is successful.
No padding takes place in this process.
In the Java code, the implementation of signing the blind message in
signConcealedMessage() is functionally identical to
In contrast, the verification in the Java code is incompatible with the above process because the Java code uses PSS as padding during verification.
A compatible Java code would be for instance:
We are trying to make a JWT token for Apple Search Ads using the KJUR jws library. We are using the API documents from Apple:
We are generating a private key (prime256v1 curve):
openssl ecparam -genkey -name prime256v1 -noout -out private-key.pem
Next we are generating a public key from the private key:
openssl ec -in private-key.pem -pubout -out public-key.pem
Next we setup the header and payload:...
ANSWERAnswered 2022-Mar-02 at 07:47
The issue is caused by an incorrect import of the key.
The posted key is a PEM encoded private key in SEC1 format. In
getKey() the key is passed in JWK format, specifying the raw private key
d. The PEM encoded SEC1 key is used as the value for
d. This is incorrect because the raw private key is not identical to the SEC1 key, but is merely contained within it.
To fix the problem, the key must be imported correctly. jsrsasign also supports the import of a PEM encoded key in SEC1 format, but then it also needs the EC parameters, s. e.g. here. For prime256v1 aka secp256r1 this is:
I trying to get the RSA signature as described in Annex A2.1 of EMV book 2. As I understand it was described in ISO9796-2 as scheme 1, option 1. So, the resulting signature should contain a Header equal to '6A' and a Trailer equal to 'BC'.
The algorithms ALG_RSA_SHA_ISO9796 and ALG_RSA_SHA_ISO9796_MR are the only suitable that I could find. But they acting like scheme 1, option 2 with a Trailer equal to '33cc'
Is it possible to get a signature with Trailer = 'BC'?
Javacard example code:...
ANSWERAnswered 2022-Feb-24 at 10:46
You can generate such signature using
Cipher.ALG_RSA_NOPAD in decrypt mode.
Hello I am trying to transfer a custom SPL token with the solana-wallet adapter. However i am having trouble getting the wallet's secret key/signing the transaction.
I've looked at these answers for writing the transfer code but i need to get the Singer and i have trouble figuring out how with solana-wallet adapter. These examples hardcode the secret key and since i'm using a wallet extension this is not possible.
How can you transfer SOL using the web3.js sdk for Solana?
How to transfer custom token by '@solana/web3.js'
according to this issue on the webadapter repo https://github.com/solana-labs/wallet-adapter/issues/120 you need to:
- Create a @solana/web3.js Transaction object and add instructions to it
- Sign the transaction with the wallet
- Send the transaction over a Connection
But i am having difficulty finding examples or documentation as to how to do step 1 and 2....
ANSWERAnswered 2021-Dec-06 at 13:51
So i found a way to do this, it requires some cleanup and error handling but allows for a custom token transaction via
I have a base64-encoded public key in DER format. In Python, how can I convert it into a COSE key?
Here is my failed attempt:...
ANSWERAnswered 2022-Jan-01 at 07:49
The posted key is an EC key for curve P-256 in X.509 format.
With an ASN.1 parser (e.g. https://lapo.it/asn1js/) the x and y coordinates can be determined:
I'm switching from the pure Python
ecdsa library to the much faster
coincurve library for signing data. I would also like to switch to
coincurve for verifying the signatures (including the old signatures created by the
It appears that signatures created with
ecdsa are not (always?) valid in
coincurve. Could someone please explain why this is not working? Also, it seems that
cryptography library is able to validate both
ecdsa signatures and
coincurve signatures without issues, consistently.
What is even more confusing, if you run below script a few times, is that sometimes it prints point 3 and other times it does not. Why would
coincurve only occasionally find the signature valid?
ANSWERAnswered 2021-Dec-25 at 14:41
Bitcoin and the coincurve library use canonical signatures while this is not true for the ecdsa library.
What does canonical signature mean?
In general, if
(r,s) is a valid signature, then
(r,s') := (r,-s mod n) is also a valid signature (
n is the order of the base point).
A canonical signature uses the value
s' = -s mod n = n - s instead of
s, i.e. the signature
(r, n-s), if
s > n/2, s. e.g. here.
All signatures from the ecdsa library that were not been successfully validated by the coincurve library in your test program have an
s > n/2 and thus are not canonical, whereas those that were successfully validated are canonical.
So the fix is simply to canonize the signature of the ecdsa library, e.g.:
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