How Multi-Currency Wallets Work—One Key, Many Coins
One question we hear a lot from our customers is “Do you support xxx coin?” While our REAL Series Cold Storage cards support many popular coins like Bitcoin and Ethereum, not all coins are compatible. So, if a multi-currency wallet can handle hundreds of coins, tokens, and even NFTs, why can’t it support all of them? How exactly do these wallets work, anyway? How can one key manage so many coins?
The answer lies in cryptography—the foundation of all cryptocurrencies. In this post, we’ll explain how multi-currency wallets work, why they don’t support every coin, and how to secure your crypto with a real-world solution.
What is a Multi-Currency Wallet?
While single-currency wallets exist (like Ballet’s Cold Storage Coins for BTC or XRP), most modern crypto wallets—whether they’re software-based or a hardware device—support multiple currencies. Wallets like the REAL Series Cold Storage allow you to hold and manage multiple types of cryptocurrency with one device or app and one private key.
Think of it like a digital vault versus a billfold and coinpurse: a multi-currency wallet lets you hold Bitcoin, XRP, and more all in the same place, rather than needing a separate wallet for each coin. This is possible because of a shared commonality between cryptocurrencies you might not be aware of.
What Is Cryptography?
As you may have guessed, the “crypto” part of cryptocurrency—which originates from an Ancient Greek word meaning "hidden" or "secret”—stems from cryptography. Essentially, cryptography is the study and practice of sending secure, secret information between parties. The sender “encrypts” the message or data so that only the recipient can “decrypt” and read it.
For digital currencies, cryptography uses highly complex mathematical algorithms to protect sensitive data from unauthorized access, ensuring transactions are secure, confidential, and resistant to tampering.
There are two primary forms of cryptography: symmetric and asymmetric. Symmetric cryptography is used for tasks like encrypting wallet data, while cryptocurrencies rely primarily on asymmetric cryptography for secure addresses and transactions. This cryptographic foundation is what makes multi-currency wallets possible, as many blockchains share the same encryption method.
The Cryptographic Commonality
Most major cryptocurrencies use elliptic curve cryptography (ECC), which allows a randomly generated private key to be transformed into a corresponding public key. The public key generates a wallet address that can be shared freely, while the private key is kept confidential and used to verify digital signatures and authenticate transactions securely. ECC is the shared commonality that allows multi-currency wallets to function; coins and tokens that use the same elliptic curve can also use the same private key.
For example, many chains use the secp256k1 curve, a specific mathematical formula used by Bitcoin and other blockchains to create secure key pairs. All cryptocurrencies using the secp256k1 curve use 256-bit (32-byte) private keys. The private key can be encoded in various formats, but encoding is just formatting for display—it doesn’t change the underlying key value. As long as it’s a 256-bit value within the valid range, it can be used in a compatible ECC scheme for generating a public key.
Here’s a simple breakdown of how a multi-currency wallet uses one key for many coins:
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A 256-bit private key is randomly generated.
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The secp256k1 curve transforms it into a public key.
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Each blockchain uses its own rules (derivation path) to turn the public key into a unique address.
The same 256-bit private key can generate valid addresses across multiple blockchains, as long as they use the same elliptic curve. The address derivation path and encoding format change for each coin, but the private key and underlying ECC math stays the same.
→ Keep in mind that if a single private key is compromised, every address and asset tied to that key—across all supported blockchains—can be accessed. That’s why securing your wallet is critical: store it safely and never share your private key.
So Why Don’t All Multi-Currency Wallets Support All Coins?
As we’ve seen, multi-currency wallets rely on shared cryptography like the secp256k1 curve. However, some blockchains do not use the secp256k1 curve, and are therefore incompatible with shared-key wallets. For example, Stellar and Polkadot use the Ed25519 curve, while NEO uses the secp256r1 curve. NFTs, such as those following Ethereum’s ERC-721 or ERC-1155 standards, can only be managed if the wallet supports the underlying blockchain.
Many wallets also suffer from practical constraints. Supporting thousands of coins requires storage and power, which can limit what a wallet can support and may require firmware or hardware updates over time. Additionally, adding support for a blockchain takes time, as developers must understand the new chain's architecture and create and test derivation logic.
Conclusion: Simplicity Through Shared Cryptography
Multi-cryptocurrency wallets leverage the fact that many blockchains share the same cryptographic foundation. With one secure 256-bit private key, a wallet can derive unique addresses for dozens of networks, which simplifies wallet management, reduces the chance of mismanaging multiple private keys, and supports diverse crypto portfolios.
As blockchain adoption grows, understanding how shared-key wallets work empowers users to make informed decisions—whether you're managing a few coins or a hundred.
Ballet Wallets: A Real-World Implementation
Multi-currency wallets simplify crypto management by using one private key for multiple blockchains, but their limitations highlight the importance of choosing a wallet that aligns with your portfolio. Ballet’s REAL Series Cold Storage offers a secure, user-friendly solution.
How It Works:
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One 256-bit private key is generated using the secp256k1 curve.
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From that key, addresses are pre-derived with cryptographically unique outputs for each supported blockchain.
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The wallet shows the primary deposit address on the front (e.g. a REAL Bitcoin wallet will display a BTC address, while a REAL XRP wallet will display an XRP address).
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Subsequent addresses can be activated through the Ballet Crypto app, and you can see them displayed there.
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The encrypted private key remains hidden on the physical card beneath the primary QR code sticker. You can then access all supported assets using the same private key.
Because it’s offline and tamper-evident, Ballet offers a straightforward solution for secure, multi-coin cold storage.
Learn more and shop securely at store.ballet.com
