You see, to create a public key from a private one, Bitcoin uses the ECDSA, or Elliptic Curve Digital Signature Algorithm. More specifically, it uses one particular curve called secp256k1. Now, this curve has an order of 256 bits, takes 256 bits as input, and outputs 256-bit integers. Bitcoin Brainwallet Cracking Tools Jack Huang Bitcoin Sunday January 31st, 2016 20:31 Bitcoin. ECDSA private key (random number / secret exponent). No, this is not a tool to crack or generate private key for a given bitcoin address. Reply; James. Bitcoin addresses and private keys are not all that random. Please take caution. Posted by 6 years ago. Generate the private key and then address for each of those and test against a dump of all address with balances from a bitcoind.

Brainwallets are Bitcoin wallets generated uniquely from a passphrase that the users keeps in his mind so that it is required and sufficient to move the funds.

But what is actually the process that takes a password and spits a Bitcoin wallet address? Let’s dissect it.

1. From a password to a secret value

Mar 29, 2018 The bu tool is obsolete, which makes this post not-so-useful. Look at this file instead. The command line utility bu (for Bitcoin utilities) is included with my Python-based pycoin library. This utility makes it easy to deal with Bitcoin private keys and addresses in their native and various intermediate formats. Apr 30, 2018  Bitcoin private Key and Address with balance generator Free BitCoin Android App https://data.hu/get/11515002/Coin-ap. Client-side Bitcoin address and deterministic wallets generator, Base58 converter, transaction builder, signing and verifying messages with Bitcoin address. Passphrase Secret Exponent Private Key ASN.1 Key. Secret Exponent. Point Conversion. Uncompressed Compressed. Signature Type. Mar 27, 2018  Generate A Bitcoin Address And Private Key. Generate a bitcoin address and private key I need your help. Because generating the public key involves exponentiation, and there is no known way to go from the public key to the secret exponent. Lets take a look at. 2017 Author has 191 answers and 24k answer views I have joined a new bitcoin.

So, we have a password, but we need a fixed-size (256-bit) secret value to make our private key. This step can be done in a number of ways as it boils down to hashing the password but is crucial to the strength of the resulting brainwallet.

Let’s have a look at how popular Brainwallet generators do it. (As of 20131204)

A lot of them just take the unsalted SHA256 hash of the password. This is wrong. Because SHA256 is fast and that means that an attacker can pregenerate huge tables of all possible brainwallets to monitor and empty them (Spoiler: they do). This kind of thing – turning a human supplied password into a public hash – is exactly what password stretching are for, and not using them here is an oversight as bad as not using them to store website user passwords, if not worse since here the hashes (the addresses) are public by default.

(Hint: use WarpWallet. It’s built by people who know what they are doing, and employs a proper KDF, making attacking your wallet really difficult.)

2. From the secret value to a private key

This is step is trivial. Actually, the output of the hashing above taken as a 256-bit unsigned number is already the private key, what is commonly called the secret exponent.

But we are used to see those pretty private keys beginning with a 5, so let’s see how it is encoded. That format is called WIF, Wallet import format, and it is pretty handy as it has checksumming built in and employs a charset without confusing characters (Base58Check) – exactly like a Bitcoin address.

A snippet is worth a thousand words:

3. From a private key to a public key

As Wikipedia tells us a ECDSA private key is just the scalar product of a private key (the secret exponent) and the curve – secp256k1 for Bitcoin – base point. How to do that is complex, but let’s just take it for granted, as you’ll either use a librarty for this or research further by yourself.

What we get out of that operation is a pair (x, y) denoting a point on the curve, our public key.

4. From the public key to a Bitcoin address

We’re almost there! Now we just need to turn that ECDSA public key into a standard Bitcoin address.

The process is the same as point 4, executed on the SHA256+RIPEMD160 hash of the packed x and y values. Go go snippet:

And it’s done!

What is a Bitcoin private key?

A Bitcoin private key is a secret number which every Bitcoin wallet has. This 256-bit number can be represented in several formats: in hexadecimal – 256 bits, in hexadecimal is 32 bytes, or 64 characters in the range 0-9 or A-F, Base64 string, a WIF key, or a mnemonic phrase.

Here is an example:

E9873D79C6D87DC0FB6A5778633389F4453213303DA61F20BD67FC233AA33262

First method

The simplest way of generating a 32-byte integer is to use an RNG library in the language you know. Here are a few examples in Python:

bits = random.getrandbits(256)

/skyrim-steam-key-generator-online.html. # 30848827712021293731208415302456569301499384654877289245795786476741155372082

bits_hex = hex(bits)

# 0x4433d156e8c53bf5b50af07aa95a29436f29a94e0ccc5d58df8e57bdc8583c32

private_key = bits_hex[2:]

# 4433d156e8c53bf5b50af07aa95a29436f29a94e0ccc5d58df8e57bdc8583c32

However, normal RNG libraries are not the most secure options of generating a key. As the generated string is based on a seed, the seed represents the current time. And if you know the time, several brute-force attacks can be applied to it.

Cryptographically strong RNG

In addition to a standard RNG method, Programming languages provide a RNG for specific cryptographic tasks. As the entropy is generated directly from the operating system, this method ensures more security.

It makes this RNG more difficult to reproduce as you can’t determine the time of generation or the seed because it lacks one. No seed is required as it’s created by the program itself.

In Python, you can implement the cryptographically strong RNG in the secret module.

bits = secrets.randbits(256)

# 46518555179467323509970270980993648640987722172281263586388328188640792550961

bits_hex = hex(bits)

# 0x66d891b5ed7f51e5044be6a7ebe4e2eae32b960f5aa0883f7cc0ce4fd6921e31

private_key = bits_hex[2:]

# 66d891b5ed7f51e5044be6a7ebe4e2eae32b960f5aa0883f7cc0ce4fd6921e31

Specialized sites

There are several sites which can generate these numbers randomly for you. Random.org is a site which randomly generates numbers for various purposes. Another popular site is bitaddress.org specifically designed to generate Bitcoin private keys.

As you have no way of knowing if random.org keeps or records any of the generated numbers, it is not such a secure option.

Bitaddress.org, however, is an open source, which means you can check its code to see what it does, and you can also download and run it on your computer in offline mode.

The program uses your mouse or key movements to generate entropy. This makes it highly improbable to reproduce your results.

Then, the private key is delivered in a compressed WIF format, but we will make the algorithm return a hex string which will be required later on for a public key generation.

Bitaddress first initializes a byte array, trying to get as much entropy as possible from your computer. It fills the array with the user input, and then it generates a private key. The service uses the 256-byte array to store entropy. This array is filled in cycles, so when the array is filled for the first time, the pointer resets to zero, the array is filled out again.

After an array is initiated from Window.crypto, it writes a timestamp to generate 4 additional bytes of entropy. It collects data such as the size of the screen, your time zone, information about browser plugins, your locale, among others to add another 6 bytes.

Then after initialization, the program repeatedly waits for the user input to rewrite initial bytes. When the cursor is moved, the position of the cursor is written. When buttons are pressed, the char code of the pressed button is written by the program.

The accumulated entropy to generate a private key of 32 bytes by using an RNG algorithm is called ARC4.

The DIY Version

You can also create your own version of Bitaddress. We will not be gathering data regarding the user’s computer and location. The entropy will be generated only by text, as it’s rather difficult to initialize a position of the cursor via a Python script.

The byte array will be initialized with a cryptographic RNG, then the timestamp will be filled, followed by the filling with a user-generated string.

After filling the second seed pool, the library will allow you to create the key.

Initializing the pool

We insert several bytes from cryptographic RNG and a timestamp. __seed_int and __seed_byte are two methods that will help insert the entropy into the pool array. We will also use the secrets module in our example.

def __init_pool(self):

for i in range(self.POOL_SIZE):

random_byte = secrets.randbits(8)

self.__seed_byte(random_byte)

time_int = int(time.time())

self.__seed_int(time_int)

/microsoft-office-2010-product-activation-key-generator.html. def __seed_int(self, n):

self.__seed_byte(n)

self.__seed_byte(n >> 8)

self.__seed_byte(n >> 16)

self.__seed_byte(n >> 24)

def __seed_byte(self, n):

self.pool[self.pool_pointer] ^= n & 255

self.pool_pointer += 1

if self.pool_pointer >= self.POOL_SIZE:

self.pool_pointer = 0

Here, we insert a timestamp and then we input each character of the string.

def seed_input(self, str_input):

time_int = int(time.time())

self.__seed_int(time_int)

for char in str_input:

char_code = ord(char)

self.__seed_byte(char_code)

Generating the private key

In order to generate a 32-byte number with our pool, we have to use a shared object that is employed by any code that is running in one script.

To save our entropy each time a key is generated, the state we stopped at will be remembered and set for the next time a key will be generated.

Now we just need to ensure that our key is in range (1, CURVE_ORDER), which is required for ECDSA private keys. The CURVE_ORDER is the secp256k1 curve’s order.

We will be converting the key to hex, and remove the ‘0x’ part.

def generate_key(self):

big_int = self.__generate_big_int()

big_int = big_int % (self.CURVE_ORDER — 1) # key < curve order

big_int = big_int + 1 # key > 0

key = hex(big_int)[2:]

return key

def __generate_big_int(self):

if self.prng_state is None:

seed = int.from_bytes(self.pool, byteorder=’big’, signed=False)

random.seed(seed)

self.prng_state = random.getstate()

random.setstate(self.prng_state)

big_int = random.getrandbits(self.KEY_BYTES * 8)

Generate Bitcoin Private Key Based On Secret Exponent Video

self.prng_state = random.getstate()

return big_int

In order to use the library, you can generate a private key using the following code:

kg = KeyGenerator()

kg.seed_input

kg.generate_key()

# 60cf347dbc59d31c1358c8e5cf5e45b822ab85b79cb32a9f3d98184779a9efc2

You will notice that each time you run the code you will get different results.

Conclusion

Generate Bitcoin Private Key Based On Secret Exponent 1

Varying in terms of the level of security and ease of implementation, there are many methods that can help you generate your private keys.