Stealth25519 Python Package

The Stealth25519 Python package provides functionality for the generation, verification, and signing of stealth addresses using the standard ed25519 algorithm with the ECDH protocol.

Stealth Address Features

• The sender can generate a stealth address using the public view and spend key of the recipient.
• The recipient can use their public spend key and private view key to identify transactions intended for them.
• The recipient can sign transactions for all transactions that belong to them.
• The signature generated by the recipient can be verified by anyone with the stealth address public key.

Installation

pip install stealth25519

Example Usage

Generating and Loading Private Keys

from cryptography.hazmat.primitives.asymmetric import ed25519
from stealth25519.key import PrivateKey, PublicKey

# Generate or load private key from cryptography or any other library as bytes array
private_spend_key_ = '6e2096a4aeb83752be2c2072d26d8c526c9bb7c5957289fc6feb85bd7da8dbf3'
private_view_key_ = ed25519.Ed25519PrivateKey.generate()

private_spend_key = PrivateKey(bytes.fromhex( private_spend_key_))
private_view_key = PrivateKey(private_view_key_.private_bytes_raw())

public_spend_key = private_spend_key.generatePublicKey()
public_view_key = private_view_key.generatePublicKey()

print('Private spend key: ', private_spend_key)
print('Private view key: ', private_view_key)
print('Public spend key: ', public_spend_key)
print('Public view key: ', public_view_key)

Output

After generating and loading the private keys, the output would be:

Private spend key:  6e2096a4aeb83752be2c2072d26d8c526c9bb7c5957289fc6feb85bd7da8dbf3
Private view key:   0f516f860b87d991924be8dbe00f15d8633ee6168b77e38ef7646771d8056d56
Public spend key:   c32dd358fa8fbea62d3b875c7b0db1631a39b643ff7a8f180de4878b2298be06
Public view key:    874e1029399477a9537b5015580ff8cc4701ecd8ced251fbe75ba7b9cc3fb3be

Generating a Stealth Address

from stealth25519.generator import StealthAddressGenerator

public_spend_key_bytes = bytes.fromhex('18a498c68461e39dd180745e5aa1faacbc9b8a5f74a7eb25b5038b66db0a4af6')
public_view_key_bytes = bytes.fromhex('b52c33b513c26e17b7105cb1ed1c7022ef00f3967aaac0ff8bd9d15ccee4d94e')

public_spend_key = PublicKey(public_spend_key_bytes)
public_view_key = PublicKey(public_view_key_bytes)

generator = StealthAddressGenerator(public_spend_key, public_view_key, hash_function = sha512)
stealth_address = generator.generate()
print('Stealth Address\n', stealth_address)

Output

After generating the stealth address the output would be:

Stealth Address
R: f694a725eade1f938797a87ba09d505f4be4358c1e8a865a3ef0ae202bb8b827
P: 573fff985d6407e747a845ff9f6d245b65b68beb3738837d207943f7697a6338

Verifying a Stealth Address

from stealth25519.verifier import StealthAddressVerifier

private_view_key_bytes = bytes.fromhex('8cdc2d3879363eff3c187ee494c7154ac63a4b94c1814488fd46c4f2bafc2239')
public_spend_key_bytes = bytes.fromhex('18a498c68461e39dd180745e5aa1faacbc9b8a5f74a7eb25b5038b66db0a4af6')
R = bytes.fromhex('f694a725eade1f938797a87ba09d505f4be4358c1e8a865a3ef0ae202bb8b827')
P = bytes.fromhex('573fff985d6407e747a845ff9f6d245b65b68beb3738837d207943f7697a6338')

private_view_key = PrivateKey(private_view_key_bytes)
public_spend_key = PublicKey(public_spend_key_bytes)

stealth_address = StealthAddress(R, P)
verifier = StealthAddressVerifier(private_view_key, public_spend_key, hash_function = sha512)
results = verifier.verify(stealth_address)

print('Stealth address verified: ', results)

Output

The verification of the stealth address would output:

Stealth address verified:  True

Signing a Stealth Address

from stealth25519.signer import StealthAddressSigner

private_spend_key_bytes = bytes.fromhex('da4956d53efc1c48472080ca284948399ef5dcb1feb47ebd5017330ca2416c30')
private_view_key_bytes = bytes.fromhex('8cdc2d3879363eff3c187ee494c7154ac63a4b94c1814488fd46c4f2bafc2239')
R = bytes.fromhex('f694a725eade1f938797a87ba09d505f4be4358c1e8a865a3ef0ae202bb8b827')
P = bytes.fromhex('573fff985d6407e747a845ff9f6d245b65b68beb3738837d207943f7697a6338')

private_spend_key = PrivateKey(private_spend_key_bytes)
private_view_key = PrivateKey(private_view_key_bytes)

msg = b'somedata'
stealth_address = StealthAddress(R, P)
signer = StealthAddressSigner(private_spend_key, private_view_key, hash_function = sha512)
sig = signer.sign(stealth_address, msg)
print('Stealth signature: ', sig.hex())

Output

Stealth signature:  56dcf17a9fd91b7d3d0dffc7ea86fd1cb1dda94caff964c2533c63ecd52166377684fa60f2cfe5258f9e5c8247db4e5003a73c1d0fbd42c56f31a7b996089404

Signature Verification

The signature generated using the private spend key can be verified using the public key of the stealth address (P). This verification can be done by anyone using the ed25519 signature algorithm (ECDSA).

from cryptography.hazmat.primitives.asymmetric import ed25519

def verify_ed25519_signature(public_key_bytes, signature_bytes, message):
    public_key = ed25519.Ed25519PublicKey.from_public_bytes(public_key_bytes)
    try:
        public_key.verify(signature_bytes, message)
        return True
    except Exception as e:
        print(f"Signature verification failed: {str(e)}")
        return False

public_key_hex = '1d3796436ecf22b674f60990945fb09d4a5dd4ad6c16e04dd20ff46e71935fc5'
signature_hex = '56dcf17a9fd91b7d3d0dffc7ea86fd1cb1dda94caff964c2533c63ecd52166377684fa60f2cfe5258f9e5c8247db4e5003a73c1d0fbd42c56f31a7b996089404'
message = b'somedata'

public_key_bytes = bytes.fromhex(public_key_hex)
signature_bytes = bytes.fromhex(signature_hex)


verification_result = verify_ed25519_signature(public_key_bytes, signature_bytes, message)
print('Signature verification result:', verification_result)

Output

Signature verification result: True

Generate and verify stealth address using custom hash function (Keccak256)

This Python code snippet demonstrates the generation and verification of stealth addresses using a custom hash function, specifically Keccak256.

from Crypto.Hash import keccak

def keccak256(s):
    keccak_hash = keccak.new(digest_bits=256)
    keccak_hash.update(s)
    return keccak_hash.digest()

# Generating and verifying stealth addresses with keccak

sa_generator = StealthAddressGenerator(public_spend_key, public_view_key, keccak256)
stealth_address = sa_generator.generate()
print('Stealth Address\n', stealth_address)

sa_verifier = StealthAddressVerifier(private_view_key, public_spend_key, keccak256)
verified = sa_verifier.verify(stealth_address)
print('Stealth Address Verified: ', verified)

Note: The code assumes that the necessary variables (public_spend_key, public_view_key, private_view_key) are defined before this snippet is executed.

Output

Stealth Address
R: c4904e7df617dd93a02375771b76270950b22eec968ad82bc903f06bf8508c3c
P: 14ec8b2ae19fa492423e8402a63a3fd48326864c01409e9001af0066f532aeca
Stealth Address Verified:  True

Dependencies

Crypto libraries (Ensure they are installed using pip install pycryptodome cryptography)