Supposing you’ve read my previous entry about encryption (if you didn’t, then too bad for you I swear you are missing something crazy 👀) then you’ve now wrapped your head around some basics of encryption.

Congrats! Now, let’s level up and see how this wizardry we call encryption gets cozy with blockchain. Spoiler alert: It’s not just a match made in tech heaven; it’s the glue holding the whole operation together.

All right, let’s explain why pasta (encryption) and salt (blockchain) blend so well together? You see, the blockchain is this ultra-secure digital ledger, the kind that every accountant dreams of, except it’s decentralized and lives across a network of computers.

Decentralized means it’s not under anyone’s control. Not mine, not yours, or your companion or my wife’s boyfriend (I swear this is the last time with that joke).

Ok cool, but here’s the kicker: Without encryption, that super-safe ledger would be about as secure as writing your bank details on a Post-it and sticking it to your fridge.

Encryption is what makes blockchain tamper-proof, private, and secure. It’s the bodyguard that ensures only those with the right credentials can access or alter data. Whether it’s protecting your crypto transactions or keeping the integrity of a smart contract intact, encryption is the unsung hero of the blockchain universe.

Remember in "Encryption 001" where I talked about public and private keys? Good news, you’re going to see them in action here. In the world of blockchain, these keys are everything.

Here’s how they work: Every blockchain user gets a pair of keys. The public key is your identity on the blockchain, a bit like your bank account number. You can share it with others, and they can send you stuff (crypto, data, etc.).

The private key, on the other hand, is your secret code. It’s what you use to access your assets, sign transactions, and prove that “yep, it’s really me” when interacting on the blockchain.

Now, here’s where encryption does its thing: When you send a transaction on the blockchain, you sign it with your private key.

This generates a digital signature, which is then verified by the network using your public key. If the signature checks out, the transaction is approved and recorded. If not, well, good luck trying to pass that off as legit.

I’ll be brief about hashing here since it’s quite simple in all honesty. In blockchain, hashing is the process that takes any input data (a transaction, for example) and runs it through a hash function to produce a fixed-length string of characters that looks like total gibberish.

But don’t be fooled, this gibberish is unique to the input data, like a fingerprint. Change even one tiny detail of the original data, and you get a completely different hash.

This property of hashing is known as determinism, the same input will always produce the same hash, but even the smallest change in input will result in a drastically different output. This characteristic is what makes hashing so powerful for ensuring data integrity in blockchain technology.

It’s like having a secret recipe where changing even a pinch of salt completely alters the taste; once hashed, the data is so unique that it can be easily verified against any attempts at tampering.

In the blockchain, every block contains the hash of the previous block, chaining them together in a sequence that’s pretty much unbreakable. This interlinking of hashes across blocks forms what is known as the blockchain, a chain of blocks linked by their respective hashes.

The hash of each block doesn’t just include the data within that block but also the hash of the previous block, creating a secure and tamper-evident ledger.

This means if someone tries to mess with a block, for example by altering a transaction within it, the hash of that block changes, which in turn changes the hash stored in the subsequent block. This cascading effect breaks the entire chain’s continuity, making it immediately obvious that tampering has occurred.

It’s like tampering with one link in a chain and watching the whole thing fall apart. This is what gives blockchain its strong immutability and security features; once data is recorded in the blockchain, it becomes virtually impossible to alter without detection.

Hashing also plays a crucial role in the mining process within blockchain networks that use Proof of Work (PoW) as their consensus mechanism. Miners compete to solve a computational puzzle that involves finding a hash below a certain threshold by varying the input slightly (usually by changing a value called the nonce).

The first miner to find such a hash gets to add the new block to the blockchain and is rewarded with cryptocurrency. This process ensures that adding new blocks to the blockchain is computationally expensive and resource-intensive, further securing the network against malicious actors.

Lastly, remember about me being brief about hashing? Yeah I lied, but you should get used to that in this industry. Don’t blame me.

I’ve talked about it in my previous entry, but I’ll set a reminder in order to progress furthermore. Blockchain doesn’t just rely on one type of encryption. It uses both symmetric and asymmetric encryption, because hey, why settle for one layer of security when you can have two?

• Symmetric Encryption: This is your basic, straightforward encryption. You have one key that both locks and unlocks the data. It’s fast and efficient, making it great for encrypting large amounts of data on the blockchain. The downside? If someone gets their hands on the key, they can unlock everything.

• Asymmetric Encryption: This is where things get fancy. Asymmetric encryption uses two keys—one public and one private. The public key encrypts the data, and only the corresponding private key can decrypt it. This is what keeps your private key safe when you’re sending transactions on the blockchain. Even if someone intercepts your public key, they can’t do much without the private key.

Smart contracts are one of blockchain’s coolest features—they’re self-executing contracts with the terms of the agreement directly written into code. But what happens when someone tries to tamper with that code? Enter encryption.

When a smart contract is created, it’s encrypted to ensure that the code cannot be altered or tampered with once it’s deployed on the blockchain.

This encryption ensures that the contract will execute exactly as written, no matter what. It’s like setting your computer to auto-lock with a password, it runs smoothly, and nobody can mess with it unless they’ve got the key.

Let’s bring this all together with a simple real-world example. Remember the Ethereum 2.0 upgrade? It introduced a host of new features, but at its core was a push for stronger encryption.

By enhancing the security of its smart contracts and transactions, Ethereum made sure that it stayed ahead in the crypto space. It’s not the unique reason, but it’s one of them.

Another example? Privacy coins like Monero. They take encryption to the next level, using advanced techniques like ring signatures and stealth addresses to keep transactions completely private and untraceable. This makes them a go-to choice for anyone who values anonymity in the crypto world.

This is a classic, but the question makes sense. After all, we keep hearing almost everyday that X protocol or X project had failed due to a vulnerability.

If encryption is the superhero we’ve made it out to be, why do we keep hearing about blockchain projects getting hacked then huh?

Trust me when I say that: encryption is rock solid when done right, but the Achilles’ heel often lies in how it’s implemented or, more commonly, in the human factor.

Most hacks happen not because encryption failed, but because of poor key management, software vulnerabilities, or straight-up human error. Take the 2017 case of Parity Wallet as an example. Parity, a popular Ethereum wallet, was compromised due to a bug in the smart contract code that managed multi-signature wallets.

A user accidentally triggered the bug, which allowed them to take ownership of the contract and, inadvertently, lock away $300 million worth of Ether, making it irretrievable. This disaster didn’t happen because encryption failed, but because of a critical oversight in the coding and management of the smart contract.

So, while encryption is a powerful tool, it’s not a magic wand, it still requires careful handling to keep everything secure.

Yes, you do!

But no you don’t too!

Sure, you’ve just taken a big step into understanding how blockchain and encryption work together to keep everything secure, but believe me, we’ve only grazed the surface. There’s a whole universe of cryptographic wonders, vulnerabilities, and advancements still to explore.

You might be feeling pretty confident right now, and you should be but trust me, there’s more. A lot more. Like, how does post-quantum cryptography fit into all this? Or what about the latest developments in zero-knowledge proofs that are set to redefine privacy in blockchain? These are the topics that will take your understanding from "I get it" to "Whoa, now I really get it!"