Learning Objectives
By the end of this course, you will be able to:
- Explain what a blockchain wallet is and how it differs from traditional financial accounts
- Understand the complete history of digital money from e-gold to modern cryptocurrency
- Describe asymmetric cryptography, hash functions, and the secp256k1 elliptic curve
- Explain the relationship between private keys, public keys, and wallet addresses
- Understand how digital signatures provide authentication, integrity, and non-repudiation
- Compare and evaluate different wallet types (hot, cold, hardware, paper, multisig)
- Apply security best practices to protect cryptocurrency assets
- Create your own wallet using the Kenostod blockchain simulator
This course is designed for thorough learning. Plan for 2-3 hours of reading, exercises, and practice. Take breaks between sections. True understanding takes time, and the 250 KENO reward reflects that commitment.
Introduction to Blockchain Wallets
A blockchain wallet is your gateway to the world of cryptocurrency. Unlike a traditional wallet that holds physical cash, a blockchain wallet doesn't actually "store" your coins. Instead, it stores the cryptographic keys that prove you own those coins on the blockchain.
Think of it this way: the blockchain is like a giant public ledger that records who owns what. Your wallet is like having the keys to a safety deposit box — the box (your coins) sits in the bank (the blockchain), but only you have the key to access it.
Your cryptocurrency isn't actually "in" your wallet. It's recorded on the blockchain. Your wallet simply holds the keys that prove ownership and allow you to authorize transactions. This is one of the most common misconceptions in cryptocurrency.
Why Wallets Are Foundational
Every transaction on a blockchain requires proof that you're the legitimate owner of the funds. This proof comes from your wallet's digital signature — a unique cryptographic fingerprint that only your private key can create. Without this, anyone could claim to own your coins!
The wallet concept is fundamental to ALL blockchain systems, including:
- Bitcoin (BTC) — The original cryptocurrency, launched 2009
- Ethereum (ETH) — Smart contract platform with wallets that can interact with dApps
- Binance Smart Chain (BSC) — Where KENO lives! Compatible with Ethereum wallets
- Solana, Cardano, Polkadot — Each has their own wallet ecosystem
Traditional Bank Account vs. Blockchain Wallet
Understanding the differences is crucial for anyone entering the crypto space:
| Feature | Bank Account | Blockchain Wallet |
|---|---|---|
| Control | Bank controls your money | You have full control |
| Access | Can be frozen or restricted | Cannot be frozen by anyone |
| Identity | Requires ID, SSN, proof of address | Can be created anonymously |
| Hours | Business hours, 3-5 day transfers | 24/7, minutes to confirm |
| Recovery | Call the bank, prove identity | Lose your key = lose everything |
| Fees | Monthly fees, overdraft, wire fees | Small transaction fees only |
| Privacy | Bank sees all transactions | Pseudonymous on public ledger |
| Insurance | FDIC insured up to $250K | No insurance (you are the bank) |
With a blockchain wallet, you are your own bank. This means complete freedom — but also complete responsibility. There's no "forgot password" button, no customer service to call, and no way to reverse a transaction sent to the wrong address. This is why education matters, and why you're earning KENO for learning!
How Wallets Interact with the Blockchain
When you use a wallet to send cryptocurrency, here's what actually happens step by step:
-
You Create a Transaction
Your wallet software creates a message saying "Send X amount from my address to this other address." This message includes the exact amount, the recipient, and a transaction fee.
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Your Wallet Signs It
Using your private key, the wallet creates a digital signature. This signature mathematically proves you authorized this specific transaction without revealing your private key.
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Broadcast to the Network
The signed transaction is broadcast to the blockchain network. Thousands of nodes receive it and can verify the signature using your public key.
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Miners/Validators Confirm
Miners (Proof of Work) or validators (Proof of Stake) verify the signature is valid, check you have sufficient balance, and include the transaction in a new block.
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Permanent Record
Once included in a block, the transaction becomes a permanent part of the blockchain. The recipient's balance increases, yours decreases, and the record exists forever.
The History of Digital Money
To truly understand wallets and cryptocurrency, you need to understand the decades of innovation that led to Bitcoin. The idea of digital money didn't start in 2009 — it started in the 1980s.
The Timeline of Digital Currency
1983 — David Chaum's eCash
Cryptographer David Chaum invented "blind signatures" and created eCash — the first digital currency that offered true anonymity. His company DigiCash went bankrupt in 1998, but the ideas lived on. Chaum proved that mathematics could replace trust in financial transactions.
1996 — e-gold
e-gold allowed users to open accounts denominated in grams of gold. At its peak, it processed $2 billion in transactions annually. However, it was centralized (one company controlled everything), making it vulnerable to government shutdown — which happened in 2009.
1997 — Adam Back's Hashcash
Adam Back invented Hashcash, a proof-of-work system originally designed to prevent email spam. The concept of "computational work as proof" became a cornerstone of Bitcoin's mining system. Back is now CEO of Blockstream.
1998 — Wei Dai's b-money & Nick Szabo's Bit Gold
Two separate proposals for decentralized digital currency. Wei Dai's b-money proposed a system where digital money is created through computational work. Nick Szabo's Bit Gold was remarkably similar to what Bitcoin would become, including proof-of-work, timestamping, and digital property rights. Both are cited in the Bitcoin whitepaper.
2004 — Hal Finney's RPOW
Hal Finney created Reusable Proof of Work (RPOW), a system that allowed proof-of-work tokens to be reused. Finney would later become the recipient of the first-ever Bitcoin transaction from Satoshi Nakamoto.
2008 — Bitcoin Whitepaper Published
On October 31, 2008, an anonymous person (or group) using the name "Satoshi Nakamoto" published "Bitcoin: A Peer-to-Peer Electronic Cash System." The 9-page paper solved the "double-spending problem" without needing a trusted third party — one of the greatest innovations in computer science history.
2009 — Bitcoin Network Launches
On January 3, 2009, Satoshi mined the "genesis block" (Block 0), embedding the headline: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks." This was a statement about the financial system that Bitcoin was designed to replace. The first wallet was born.
2015 — Ethereum Launches Smart Contracts
Vitalik Buterin created Ethereum, extending Bitcoin's concept with programmable "smart contracts." Now wallets weren't just for sending money — they could interact with complex applications, creating an entire ecosystem of decentralized finance (DeFi).
2020 — Binance Smart Chain (BSC)
Binance launched BSC, an EVM-compatible blockchain with faster transactions and lower fees than Ethereum. KENO is a BEP-20 token on BSC, meaning it uses the same wallet technology as Ethereum but benefits from BSC's speed and affordability.
Every innovation in this timeline solved a problem that the previous system couldn't. David Chaum gave us cryptographic privacy. Adam Back gave us proof of work. Satoshi combined everything into Bitcoin. Understanding this history helps you appreciate why wallet security matters — millions of dollars have been lost by people who didn't understand the technology they were using.
The Evolution of Wallet Technology
Wallets have evolved dramatically since Bitcoin's early days:
- 2009-2011: Command-line only. Users had to run full Bitcoin nodes and manage raw key files. Extremely technical.
- 2011-2013: First GUI wallets (Bitcoin-Qt). Still required downloading the entire blockchain (100+ GB).
- 2013-2015: Web wallets and mobile wallets emerged (Blockchain.info, Mycelium). Accessibility improved dramatically.
- 2014-present: Hardware wallets (Trezor 2014, Ledger 2016) brought bank-grade security to consumers.
- 2017-present: Multi-chain wallets (MetaMask, Trust Wallet) that work across multiple blockchains.
- 2020-present: Social recovery wallets, smart contract wallets (Argent, Safe), and Account Abstraction making wallets more user-friendly.
Cryptography Foundations
Cryptography is the science of secure communication. In blockchain, we use a specific type called asymmetric cryptography (also known as public-key cryptography). This section will take you from the basics to a working understanding of the math that secures billions of dollars.
Symmetric vs. Asymmetric Cryptography
Before we dive into blockchain cryptography, you need to understand the two main types:
| Feature | Symmetric (AES, DES) | Asymmetric (RSA, ECC) |
|---|---|---|
| Keys | One shared key | Two keys (public + private) |
| Speed | Very fast | Slower |
| Key Distribution | Must share key securely | Public key is shared openly |
| Use Case | Encrypting files, disk encryption | Digital signatures, key exchange |
| Blockchain Use | Encrypting messages (Course 6) | Signing transactions (THIS!) |
Hash Functions: The Foundation
A hash function takes any input and produces a fixed-length output called a "hash" or "digest." In blockchain, we use SHA-256 (Secure Hash Algorithm, 256-bit), the same algorithm used by Bitcoin.
Key properties of cryptographic hash functions:
SHA256("Hello")
= "185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969"
SHA256("hello") // Just changed H to h
= "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
// Completely different! One character change = totally new hash
The secp256k1 Elliptic Curve
KENO (and Bitcoin, Ethereum, and most major cryptocurrencies) use a specific mathematical curve called secp256k1 for generating key pairs. This is an elliptic curve defined by the equation:
Where p is a very large prime number (2256 - 232 - 977). The security comes from the Elliptic Curve Discrete Logarithm Problem (ECDLP): given a point on the curve, it's easy to multiply it by a number, but virtually impossible to figure out what number was used just from the result.
Why secp256k1 specifically?
- Security: 256-bit security level. To brute-force a private key, you'd need to try 2256 combinations — that's more attempts than there are atoms in the observable universe.
- Efficiency: Specially constructed (non-random) parameters make computation ~30% faster than random curves.
- No backdoors: Unlike NIST curves (which some suspect may have NSA backdoors), secp256k1's parameters are transparent and verifiable.
- Standardization: Used by Bitcoin since 2009, battle-tested with trillions of dollars at stake.
While classical computers can't break secp256k1, a sufficiently powerful quantum computer theoretically could using Shor's algorithm. However, quantum-resistant cryptography (lattice-based, hash-based signatures) is being actively developed. Bitcoin and Ethereum plan to transition before quantum computers become powerful enough. This is estimated to be at least 15-20 years away.
Key Vocabulary Review
Key Pairs Deep Dive
The relationship between your private key, public key, and wallet address follows a one-way path. You can always derive the public key from the private key, and the address from the public key — but NEVER in reverse.
The Private Key
A private key is simply a random 256-bit number. That's 32 bytes, or 64 hexadecimal characters. Here's what one looks like:
"e9873d79c6d87dc0fb6a5778633389f4453213303da61f20bd67fc233aa33262"
// The total number of possible private keys:
2^256 = 1.15 x 10^77 possible keys
// For comparison, estimated atoms in the observable universe:
~10^80 atoms
// So the number of possible keys is nearly as large as the number
// of atoms in the universe. Guessing your key is impossible.
From Private Key to Public Key
The public key is derived by multiplying a "generator point" (G) on the secp256k1 curve by your private key number. This is called scalar multiplication on an elliptic curve.
const privateKey = BigInt("0xe9873d...");
const publicKey = G.multiply(privateKey); // Point on the curve
// The public key is two 256-bit numbers (x, y coordinates)
// Uncompressed format: 04 + x + y (65 bytes)
// Compressed format: 02/03 + x (33 bytes)
From Public Key to Wallet Address
The wallet address is created by hashing the public key. On Ethereum/BSC (where KENO lives), the process is:
const hash = keccak256(publicKey);
const address = "0x" + hash.slice(-40); // Last 20 bytes
// Result: "0x742d35Cc6634C0532925a3b844Bc9e7595f..."
// This is what you share with others to receive funds!
Seed Phrases (Mnemonic Recovery)
Modern wallets don't show you the raw private key. Instead, they use a seed phrase (also called mnemonic phrase) — 12 or 24 English words that encode your private key in a human-readable format.
"abandon ability able about above absent absorb abstract absurd abuse access accident"
// BIP-39 standard: 2048 possible words per position
// 12 words = 2048^12 = 2^132 possible combinations
// That's 5.4 x 10^39 possibilities — unguessable
Your seed phrase IS your wallet. Anyone who has these 12/24 words can access ALL your funds across ALL blockchains derived from that seed. Write it on paper. Store it in a safe. NEVER type it into a website. NEVER take a screenshot. NEVER store it in a text file, cloud storage, or email.
HD Wallets: One Seed, Many Accounts
Modern wallets use Hierarchical Deterministic (HD) key derivation (BIP-32/44). From a single seed phrase, your wallet can generate billions of unique addresses. Each blockchain and account gets its own derivation path:
m/44'/60'/0'/0/0 // Ethereum account 1
m/44'/60'/0'/0/1 // Ethereum account 2
m/44'/0'/0'/0/0 // Bitcoin account 1
m/44'/56'/0'/0/0 // BSC account 1 (where KENO lives)
This means one seed phrase backs up ALL your wallets across ALL blockchains. Lose the seed phrase = lose access to everything.
Digital Signatures Explained
Digital signatures are the mechanism that makes blockchain transactions trustworthy without a central authority. Every time you send KENO, your wallet creates a digital signature that proves three things:
How ECDSA Signing Works
Blockchain uses ECDSA (Elliptic Curve Digital Signature Algorithm). Here's the conceptual process:
const transaction = {
from: "0xYourAddress",
to: "0xRecipientAddress",
amount: 100, // KENO
fee: 0.5,
timestamp: 1706817600
};
// Step 2: Hash the transaction
const txHash = SHA256(JSON.stringify(transaction));
// Step 3: Sign the hash with your private key
const signature = ecdsaSign(txHash, privateKey);
// Produces (r, s, v) values — the signature
// Step 4: Anyone can verify using ONLY the public key
const isValid = ecdsaVerify(txHash, signature, publicKey);
// Returns: true (if signature matches)
// The private key is NEVER transmitted or revealed!
Signature Verification in Practice
When a node on the network receives your transaction, it performs these checks:
- Extract the Signature
Parse the (r, s, v) values from the transaction data.
- Recover the Public Key
Using the signature and transaction hash, mathematically recover the signer's public key. This is a unique property of ECDSA.
- Derive the Address
Hash the recovered public key to get the wallet address.
- Compare Addresses
If the derived address matches the "from" address in the transaction, the signature is valid. The transaction is legitimate.
In the Kenostod blockchain simulator, you'll see this process in action. When you send KENO in Course 2 (Transactions), the simulator shows you the hash, the signature components, and the verification result in real-time. This is the same process that secures billions of dollars on Bitcoin and Ethereum.
Types of Wallets
Not all wallets are created equal. Each type makes different tradeoffs between security, convenience, and control. Understanding these tradeoffs is essential for protecting your assets.
Hot Wallets (Internet Connected)
Hot wallets are connected to the internet, making them convenient but more vulnerable to hacking.
Software Wallets (Desktop/Mobile)
Applications installed on your computer or phone. Examples: MetaMask, Trust Wallet, Exodus, Electrum.
- Pros: Free, easy to use, support multiple currencies, can interact with DeFi
- Cons: Vulnerable to malware, keyloggers, and phishing attacks. If your device is compromised, your keys are compromised.
- Best for: Day-to-day transactions with small-to-medium amounts
Web Wallets (Browser-Based)
Accessed through a web browser. Examples: MyEtherWallet (MEW), Blockchain.com wallet.
- Pros: Access from any device, no installation needed
- Cons: Server could be hacked, phishing risk is high, you might be trusting a third party with your keys
- Best for: Quick access, small amounts only
Exchange Wallets (Custodial)
Wallets provided by exchanges like Coinbase, Binance, Kraken.
- Pros: Easy to use, customer support, insurance in some cases
- Cons: "Not your keys, not your coins." The exchange controls your private keys. If they get hacked or go bankrupt, you could lose everything.
- Best for: Trading, but NOT long-term storage
Cold Wallets (Offline Storage)
Cold wallets keep your private keys completely offline, making them virtually immune to remote hacking.
Hardware Wallets
Physical devices (USB-like) that store your private keys in a secure chip. Examples: Ledger Nano S/X, Trezor Model T, GridPlus Lattice1.
- Pros: Keys never leave the device, immune to malware, physical button confirmation required
- Cons: Cost ($60-$250), can be lost or damaged, supply chain attacks possible
- Best for: Long-term storage of significant amounts
Paper Wallets
Your private key and address printed on physical paper. The most basic form of cold storage.
- Pros: Free, immune to hacking, no electronic failure points
- Cons: Can be destroyed (fire, water), stolen physically, difficult to use for transactions
- Best for: Very long-term "vault" storage
Advanced Wallet Types
Multisignature (Multisig) Wallets
Require multiple private keys to authorize a transaction (e.g., 2-of-3 or 3-of-5). Used by organizations and high-value individuals.
- Example: A company treasury requires 3 out of 5 executives to sign any withdrawal
- Pros: No single point of failure, prevents insider theft
- Cons: More complex to set up and manage
Smart Contract Wallets
Wallets that are themselves smart contracts on the blockchain, enabling features impossible with regular wallets.
- Social Recovery: Designate trusted contacts who can help you recover access (Kenostod teaches this in Course 5!)
- Spending Limits: Set daily transaction limits for security
- Account Abstraction: Pay gas fees in any token, batch transactions, use sessions
The best strategy is to use multiple wallets for different purposes. Keep a small amount in a hot wallet (like MetaMask) for daily transactions and DeFi. Store the majority of your holdings in a hardware wallet (like Ledger) for security. Think of it like keeping some cash in your pocket and the rest in a safe at home.
Security Best Practices
Your private key is the ONLY thing standing between your crypto and anyone who wants to steal it. Here are the comprehensive rules of wallet security:
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Never Share Your Private Key or Seed Phrase
No legitimate service, support team, or blockchain developer will EVER ask for your private key. If someone asks, it's a scam — 100% of the time. This includes "customer support" on Discord, Telegram, Twitter DMs, and emails.
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Use Secure Backup Methods
Write your seed phrase on paper (or stamp it in metal) and store it in a secure location like a safe or safety deposit box. Consider making two copies stored in different locations. Never store it digitally — no photos, no cloud storage, no text files.
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Verify Every Address Before Sending
Always double-check the recipient address before confirming a transaction. Clipboard-hijacking malware can replace the address you copied with the attacker's address. Verify at least the first 6 and last 6 characters.
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Use Hardware Wallets for Significant Holdings
If you hold more than you'd be comfortable losing, invest in a hardware wallet. A $80 Ledger is cheap insurance for thousands of dollars in crypto.
-
Beware of Phishing
Always verify you're on the correct website before entering any wallet information. Bookmark important sites. Check the URL carefully — "metamaask.io" is not "metamask.io". Never click wallet links in emails or messages.
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Enable Two-Factor Authentication (2FA)
For any exchange accounts, enable 2FA using an authenticator app (Google Authenticator, Authy) — NOT SMS 2FA, which is vulnerable to SIM-swapping attacks.
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Keep Software Updated
Always update your wallet software, browser extensions, and operating system. Security patches fix known vulnerabilities that attackers actively exploit.
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Use Separate Devices for High-Value Transactions
Consider using a dedicated device (phone or computer) exclusively for crypto transactions. Don't install random apps or visit risky websites on this device.
In Course 5, you'll learn about Kenostod's innovative Social Recovery feature — a safety net that lets trusted guardians help you recover your wallet if you ever lose your private key. Combined with the 5-minute transaction reversal window (Course 3), Kenostod is designed to be one of the safest blockchain platforms for learners.
Real-World Case Studies
These real events demonstrate why wallet security and understanding are absolutely critical:
Case Study 1: The Mt. Gox Disaster (2014)
What happened: Mt. Gox, once handling 70% of all Bitcoin transactions globally, was hacked. 850,000 Bitcoin (worth ~$450 million at the time, over $50 billion at peak prices) were stolen.
The cause: Users trusted a centralized exchange to hold their private keys. The exchange had poor security practices, including storing keys on internet-connected servers.
The lesson: "Not your keys, not your coins." If you don't control the private keys, you don't truly own the cryptocurrency. This event is why experienced crypto users always recommend self-custody wallets.
Case Study 2: The Lost Bitcoin Fortune (Stefan Thomas, 2021)
What happened: Stefan Thomas, a programmer, lost the password to his IronKey hardware wallet containing 7,002 Bitcoin (worth over $220 million). The IronKey allows only 10 incorrect password attempts before permanently encrypting the drive. He had 2 attempts remaining.
The lesson: Backup your recovery seed phrase. A hardware wallet protects against remote attacks, but it cannot protect against human forgetfulness. Multiple secure backups of your seed phrase are essential.
Case Study 3: The $600M Ronin Bridge Hack (2022)
What happened: North Korean hackers (Lazarus Group) compromised 5 of 9 validator private keys on the Ronin Network (Axie Infinity's blockchain bridge). They drained $600 million in ETH and USDC.
The cause: The validator nodes were poorly secured, and the multisig requirement (5 of 9) was too low. One organization controlled 4 keys.
The lesson: Multisig wallets are only secure if the keys are truly distributed among independent parties. Concentration of key control defeats the purpose.
Case Study 4: The FTX Collapse (2022)
What happened: FTX, the second-largest crypto exchange, filed for bankruptcy after it was revealed that customer funds ($8 billion) were secretly transferred to sister company Alameda Research for risky trading.
The lesson: Even billion-dollar companies with celebrity endorsements can fail. The core principle remains: if someone else holds your private keys, your funds are at risk. Self-custody is the only way to guarantee your assets are safe.
Written Exercises
Complete these exercises to reinforce your understanding. Take your time — thoughtful answers demonstrate true comprehension.
Exercise 1: Explain It Like I'm Five
Your friend asks: "What's a crypto wallet?" Write an explanation using a real-world analogy (like a mailbox, locker, etc.) that a complete beginner would understand. Avoid using any technical terms.
Exercise 2: Security Scenario Analysis
You receive this message on Discord: "Hey! I'm from Kenostod Support. We noticed suspicious activity on your account. Please send us your seed phrase so we can verify your identity and protect your KENO tokens." What do you do and why?
Exercise 3: Wallet Selection
You just earned 5,250 KENO (worth $5,250) from completing all 21 Kenostod courses. Describe your wallet strategy: What type(s) of wallet would you use? How would you split your holdings? What security measures would you implement?
Exercise 4: Key Derivation Understanding
Explain why it's safe to share your public key and wallet address with anyone, but dangerous to share your private key. What mathematical property makes this possible?
Exercise 5: Historical Analysis
Choose one of the case studies above (Mt. Gox, Stefan Thomas, Ronin, or FTX). If you were in charge of security for that organization, what specific measures would you have implemented to prevent the incident?
Hands-On Lab
Now it's time to put your knowledge into action! Complete ALL of the following tasks in the Kenostod blockchain simulator.
Lab Tasks:
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Task 1: Generate a New Wallet
Go to the Wallet tab and click "Create Wallet." Observe the private key, public key, and wallet address that are generated. Notice how the address is much shorter than the public key.
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Task 2: Examine Your Key Pair
Look at your generated keys. Count the characters in each: Private key (64 hex chars), Public key (128 hex chars), Address (42 chars including 0x prefix). This confirms the derivation hierarchy you learned.
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Task 3: Create a Second Wallet
Generate another wallet. Compare the two addresses. Notice how they're completely different even though they were generated moments apart — this is because each private key is randomly generated with 2^256 possibilities.
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Task 4: Check Your Balance
New wallets receive 1,000 KENO from the faucet. Verify this appears in your balance. This simulates receiving funds to a new wallet address.
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Task 5: Explore the Interface
Browse the other tabs (Transactions, Blockchain Explorer) to see the broader ecosystem your wallet operates in. You'll learn to use these in upcoming courses.
Opens in the main platform. Complete all 5 tasks, then return here for the Final Exam!
Final Exam (15 Questions)
You must score at least 12 out of 15 correct (80%) to complete this course and earn your 250 KENO reward. Take your time and review the material if needed.
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