**How Private Keys, Public Keys, and Ethereum Addresses are Generated**
Let's start from understanding where your funds are stored.
Did you know that your funds aren’t actually stored in your wallet? All your assets, such as Ether are stored on the blockchain. So, how do you interact with or access your funds if they aren’t in your wallet? That’s where the wallet comes in.
**What is a Wallet?**
---
A wallet is software that serves as the primary user interface for interacting with Ethereum. Think of a wallet as a safe where you keep your valuables. In the world of blockchain, these valuables are your key pairs—public and private keys.
To understand public and private keys, let’s use a bank account as an analogy. When you create a bank account, you receive an account number and a PIN. The account number is like your public key, something you can share with others, while the PIN is like your private key, something you must keep secret to authorize transactions.
The primary purpose of a wallet is to store these keys so they can be used for transactions on the blockchain.
**How Are These Keys Generated?**
---
The generation of these keys is purely mathematical and follows a specific formula. However, just because there’s a formula doesn’t mean you can guess someone’s private key. The formulas used are one-way, meaning they cannot be reversed.
For example, multiplying two large prime numbers together is straightforward. But given the product of two large primes, it is very difficult to find the prime factors. Let’s say I present the number 100,160,063 and tell you it is the product of two primes. Finding those two primes is much harder for you than it was for me to multiply them to produce 100,160,063. But this can be easily inverted if I told you one of the prime factors is 10,007. All you need to do is 100,160,063 ÷ 10,007 = 10,009. This are often called Trapdoor functions while the whole concept of creating a secured function for securing information is regarded as ***CRPTOGRAPHY***.
**Which function is then used to generate Private and Public keys?**
A more advanced mathematical function called Elliptic Curve Cryptography (ECC) is used to generate private keys. ECC works on the principle of elliptic curve arithmetic, which involves operations that are easy to perform but nearly impossible to reverse. This difficulty is known as the Discrete Logarithm Problem.
**Generating the Private Key**
To generate a private key, a large random number (typically 256 bits) is created using ECC. This number is validated to ensure it fits within the required range for the specific cryptographic system, such as the secp256k1 curve used in Ethereum. The result is the private key, a crucial piece of information that must be kept secret to secure your digital assets.
**What is secp256k1?**
The secp256k1 is a specific elliptic curve used in cryptography, particularly in blockchain technologies like Bitcoin and Ethereum, to generate cryptographic keys. The name "secp256k1" breaks down as follows:
**secp:** Standards for Efficient Cryptography
**256:** A 256-bit field size
**k1:** Indicates certain mathematical properties that make the curve efficient and secure
**Generating the Public Key**
Once the private key is generated, the public key is created by multiplying the private key (k) by a predetermined point on the elliptic curve known as the Generator Point (G). The result is another point on the curve, which is the public key (K).
For example:
Private Key (k) = f8f8a2f43c8376ccb0871305060d7b27b0554d2cc72bccf41b2705608452f315
Public Key (K) = k * G
K = (x, y) where x and y are coordinates on the elliptic curve
It’s easy to generate a public key from a private key, but nearly impossible to do the reverse. The elliptic curve arithmetic is designed so that when you try to reverse the operation (K ÷ G), you get many possible answers(equivalent to points on the curve). Hence, getting an answer exactly equal to the private key(k) is a brute force search.
**Generating the Ethereum Address**
Finally, the Ethereum address is generated from the public key by passing it through the Keccak-256 hash function and selecting the last 20 bytes of the hash. Let’s break this down:
What is a Hash Function?
A hash function maps data of arbitrary size to data of fixed size. For example, if you hash the word "apple," you might get a string like 1f3870be274f6c49b3e31a0c6728957f. Even a small change, like adding an "s" to make "apples," will produce a completely different hash.
For Ethereum addresses, Keccak-256 is the hash function used.
Example:
Public Key (K) = 6e145ccef1033dea239875dd00dfb4fee6e3348b84985c92f103444683bae07b83b5c38e5e
Keccak-256 Hash = 2a5bc342ed616b5ba5732269001d3f1ef827552ae1114027bd3ecf1f086ba0f9
Ethereum Address = 001d3f1ef827552ae1114027bd3ecf1f086ba0f9
Since Ethereum addresses are hexadecimal-encoded, you’ll often see them prefixed with "0x", like this: 0x001d3f1ef827552ae1114027bd3ecf1f086ba0f9.
And that’s how your Ethereum address is generated!
In conclusion, knowing how private keys, public keys, and Ethereum addresses are created is key to feeling confident in the world of blockchain. These cryptographic tools are what keep your digital assets secure and ensure your transactions are safe. By understanding the basics, you not only protect your investments but also gain a deeper appreciation for the technology that powers cryptocurrencies.
***Thanks to Blockfuselabs for this knowledge.***