Cryptocurrency wallets fundamentals

• A. The cryptocurrency coins themselves on your device
• B. The private keys that prove ownership of your cryptocurrency ✓
• C. A copy of the entire blockchain
• D. Your government-issued identification documents

Why: A wallet stores private keys, which are used to sign transactions and prove ownership of the funds recorded on the blockchain. The coins themselves always remain on the blockchain.

• A. Inside the wallet application
• B. On a central server owned by the wallet provider
• C. On the blockchain, a distributed public ledger ✓
• D. In the user's bank account

Why: Cryptocurrency balances and transaction history are recorded on the blockchain, a distributed ledger maintained by a network of computers. Wallets only manage the keys needed to access and transfer those balances.

• A. Hot wallets are physical devices; cold wallets are software apps
• B. Hot wallets are connected to the internet; cold wallets are kept offline ✓
• C. Hot wallets hold only Bitcoin; cold wallets hold only altcoins
• D. Hot wallets are government regulated; cold wallets are not

Why: A hot wallet stays connected to the internet, making it convenient for frequent transactions but more exposed to online attacks. A cold wallet is kept offline, such as a hardware device or paper wallet, offering stronger security for long-term storage.

• A. It is a password used to log into exchange accounts
• B. It is a list of words that can regenerate your wallet's private keys if the device is lost ✓
• C. It is a code that speeds up transaction confirmations
• D. It is a public address you share to receive payments

Why: A seed phrase is typically 12 to 24 random words that can recreate all of a wallet's private keys. Anyone who has it can access the funds, so it should be stored securely and offline, and never shared.

• A. A secret key that must never be shared with anyone
• B. A password for recovering a lost wallet
• C. An identifier derived from your public key that others can use to send you funds ✓
• D. The physical location where your wallet software is stored

Why: A public address is derived from your public key and can safely be shared so others can send you cryptocurrency. It is different from the private key, which must remain secret.

• A. Signing transactions to prove ownership of funds
• B. Receiving funds and generating a wallet address that others can send to ✓
• C. Recovering a lost wallet using a seed phrase
• D. Encrypting the wallet software on your device

Why: A public key can be shared openly and is used (usually via a derived address) to receive cryptocurrency. Signing transactions is done with the private key, not the public key.

• A. The public key
• B. The wallet address
• C. The private key ✓
• D. The transaction ID

Why: The private key proves ownership and authorizes spending. Anyone who obtains it can control the associated funds, so it must never be shared.

• A. They are two unrelated random strings
• B. The public key is derived from the private key using cryptographic functions, but the reverse is computationally infeasible ✓
• C. The private key is derived from the public key by simple reversal
• D. Both keys are identical but stored in different formats

Why: Elliptic curve cryptography lets a public key be computed from a private key easily, but deriving the private key from the public key is practically impossible with current technology. This one-way relationship is what makes the system secure.

• A. The exact password used to unlock the wallet
• B. That the transaction was authorized by the owner of the private key, without revealing the private key itself ✓
• C. The current balance of the wallet
• D. The physical location of the wallet holder

Why: A signature proves authorization. Anyone with the corresponding public key can verify the signature is valid, confirming the transaction came from the key holder, while the private key stays hidden.

• A. Email the wallet provider to reset the private key
• B. Recover it using your seed phrase or backup, since there is usually no central authority to reset it ✓
• C. Wait for the network to automatically restore your key
• D. Share your public key with support staff to regenerate the private key

Why: In self-custody wallets, the seed phrase or backup is the only recovery method. No company or network can reset a private key, so losing both the key and its backup typically means losing access to the funds permanently.

• A. It is stored offline on a hardware device
• B. It is connected to the internet ✓
• C. It is printed on paper and stored in a safe
• D. It can only be used for storing fiat currency

Why: Hot wallets are connected to the internet, such as software wallets, mobile apps, and exchange wallets. This connectivity makes them convenient for frequent transactions but also more exposed to online threats like hacking and phishing.

• A. A browser extension wallet
• B. A mobile trading app
• C. A hardware wallet stored in a secure location ✓
• D. An exchange account used for daily trading

Why: Cold wallets are kept offline and are not connected to the internet. Hardware wallets are a common example, storing private keys on a physical device that signs transactions without exposing the keys to online networks.

• A. Faster transaction confirmation times
• B. Lower exposure to online hacking and remote attacks ✓
• C. Free access to decentralized exchanges
• D. Automatic backup of funds to the cloud

Why: Because cold wallets are offline, attackers on the internet cannot directly access the private keys. This significantly reduces the risk of remote hacking, making cold storage preferred for holding large amounts of cryptocurrency long term.

• A. A paper wallet stored in a vault
• B. A hardware wallet kept in a safe deposit box
• C. A hot wallet, due to its convenience and quick access ✓
• D. A cold wallet that is rarely accessed

Why: Hot wallets provide quick and easy access to funds, which suits frequent transactions. While they carry higher security risks, their convenience makes them practical for everyday spending and trading, whereas cold wallets are better for long-term storage.

• A. They cannot be backed up or recovered
• B. They may be vulnerable to malware, phishing, and hacking ✓
• C. They require physical delivery to the owner
• D. They only support one type of cryptocurrency

Why: Since hot wallets are connected to the internet, they can be targeted by malware, phishing scams, and hacking attempts. Users should protect them with strong passwords, two-factor authentication, and by keeping only small amounts in them.

• A. A password used to log into your exchange account
• B. A list of typically 12 to 24 random words that can regenerate your wallet's private keys ✓
• C. A transaction ID that proves you sent cryptocurrency
• D. An encrypted file stored on the blockchain that holds your balance

Why: A seed phrase is a sequence of usually 12 to 24 words generated from random entropy. It encodes the master key from which all of a wallet's private keys and addresses can be derived, so anyone who has it can control the funds.

• A. In a screenshot saved to your phone's photo gallery
• B. In a plain text file in your email drafts
• C. Written by hand on paper or engraved on metal and kept in a secure physical location ✓
• D. Shared with a support agent so they can help if you lose access

Why: Offline physical storage such as handwritten paper or metal backups protects against hacking, device failure, and fire or water damage better than digital copies. Digital storage exposes the phrase to malware and cloud breaches.

• A. Because it expires after the first use
• B. Because legitimate support staff never need it, and anyone who has it can take full control of your funds ✓
• C. Because sharing it only lets the other person view your balance
• D. Because it can only be used on the device where it was originally created

Why: The seed phrase grants complete control over the wallet. Reputable wallet providers will never ask for it, so any request for your seed phrase is almost certainly a scam.

• A. Take a photo of it so you can access it anywhere
• B. Write it down accurately, verify the words in the order shown, and store it offline in a secure place ✓
• C. Save it in a note on your phone so you can copy it when needed
• D. Send it to yourself by email as a backup

Why: Recording the words exactly, confirming them in the order given, and storing them offline is the standard backup process. Digital copies in photos, notes, or email are vulnerable to theft and hacking.

• A. Keep one copy in your home safe and never make another
• B. Keep multiple copies in separate secure locations so a single disaster such as a fire or theft cannot destroy every copy ✓
• C. Store copies in every cloud storage account you own for redundancy
• D. Give one copy to each friend so they can help you recover it

Why: Geographically separated, offline copies protect against localized loss such as fire, flood, or theft while avoiding the exposure created by cloud storage or sharing with others. Redundancy only helps if the copies are kept secure and apart.

• A. Your wallet's password only
• B. The recovery (seed) phrase ✓
• C. Your email address
• D. The wallet's app version number

Why: The recovery phrase is a set of words that can restore your wallet and its funds on any compatible device. Anyone who has it can take your funds, and if you lose it you may be unable to recover your wallet, so it should be stored securely offline.

• A. In a screenshot saved to your phone
• B. In a cloud document shared with family
• C. On paper, stored in a secure physical location ✓
• D. In an email draft to yourself

Why: Writing the phrase on paper and keeping it in a secure physical location protects it from online hacks. Digital copies like screenshots, cloud files, and emails can be accessed by hackers or leaked through account breaches.

• A. To increase the wallet's transaction speed
• B. To confirm the receiving address works and funds arrive correctly ✓
• C. To activate the wallet's security features
• D. To earn a bonus from the network

Why: Cryptocurrency transactions are generally irreversible, and a mistyped or wrong address can send funds to nowhere. A small test transfer lets you verify the address and the process before risking a larger amount.

• A. The wallet asks you to back up your recovery phrase
• B. Someone asks for your recovery phrase to 'verify' your account ✓
• C. The app prompts you to update to the latest version
• D. The wallet requires a password to open

Why: Legitimate wallet providers will never ask for your recovery phrase. Anyone requesting it, whether through a message, website, or phone call, is attempting to steal your funds.

• A. Share the wallet's download link with friends
• B. Verify the app is from the official source and check its authenticity ✓
• C. Immediately deposit your largest holdings
• D. Disable all security settings for faster access

Why: Fake wallet apps are a common scam vector. Downloading only from the official website or app store and verifying the publisher helps protect you from malicious software that could steal your recovery phrase or funds.

• A. To mine new cryptocurrency coins faster
• B. To store private keys offline, away from internet-connected devices ✓
• C. To speed up cryptocurrency transaction confirmations
• D. To exchange one cryptocurrency for another automatically

Why: Hardware wallets keep private keys isolated on a dedicated device that is rarely connected to the internet, which greatly reduces exposure to malware and online attacks.

• A. To unlock the hardware wallet's screen each time you use it
• B. To encrypt transactions before they are broadcast to the network
• C. To restore access to your wallet's funds if the device is lost or damaged ✓
• D. To verify the identity of the exchange you are using

Why: The recovery phrase is a sequence of words that can regenerate your private keys on a new device, so it is the key backup for recovering funds.

• A. In a cloud note app so you can access it from any device
• B. In an email draft saved to your account
• C. Written on paper and stored in a secure, private location ✓
• D. As a photo saved on your phone's camera roll

Why: A paper backup kept offline in a secure location is not exposed to hacking, data breaches, or device theft the way digital copies are.

• A. Manufacturers offer larger storage capacity than third-party sellers
• B. Devices bought from unofficial sources may be tampered with or preloaded with a compromised seed phrase ✓
• C. Third-party sellers charge higher prices for the same device
• D. Official devices are the only ones compatible with mobile apps

Why: Tampered devices can come with attacker-generated seed phrases, so buying from unverified sellers risks losing all funds to the person who set up the device.

• A. Sharing your recovery phrase with support staff to verify your identity
• B. Entering your recovery phrase into any website that asks for it to confirm ownership
• C. Never entering your recovery phrase into a computer or website, since legitimate wallets never ask for it ✓
• D. Keeping your wallet software disabled unless you are making a transaction

Why: Your recovery phrase should never be typed into a computer, phone, or website; legitimate wallet providers and support teams will never request it.

• A. That the transaction fee is zero
• B. That the recipient's wallet address is correct and supports the same network ✓
• C. That the recipient has posted on social media recently
• D. That the wallet app has the latest color theme installed

Why: Blockchain transactions are generally irreversible, and sending to a wrong address or to a wallet on an incompatible network can result in permanent loss of funds. Verifying the address and network before sending is essential.

• A. A monthly subscription charged by the wallet provider
• B. A tax paid to the government on every transfer
• C. A payment to network validators or miners for processing and including your transaction in a block ✓
• D. A penalty applied when a transaction fails

Why: Transaction fees compensate the participants who validate and record transactions on the blockchain. Higher fees often lead to faster confirmation during periods of network congestion.

• A. The recipient has accepted the funds
• B. The transaction has been included in a block and added to the blockchain ✓
• C. The sender's wallet has been verified by the exchange
• D. The transaction fee has been refunded

Why: A confirmation means the transaction has been recorded in a block on the blockchain. Additional confirmations, where more blocks are added after it, make the transaction increasingly secure against reversal.

• A. Share your private key so the sender can verify the wallet
• B. Provide your wallet's public receiving address, and double-check it on your wallet app ✓
• C. Send a small test amount back to the sender's personal email
• D. Give the sender your seed phrase so they can deposit directly

Why: A public receiving address is safe to share and is what senders need. Your private key and seed phrase must never be shared, as anyone with them can control your funds.

• A. The blockchain has been permanently shut down
• B. The transaction fee was too low for current network demand ✓
• C. The recipient has blocked incoming transactions
• D. The wallet automatically deletes pending transactions after one minute

Why: When the network is busy, validators prioritize transactions with higher fees. A transaction with a low fee may wait longer to be confirmed, though it can often be sped up or may eventually be processed.