Mixing up the two is one of the costliest mistakes a new crypto user can make. This article explains what each one does, how they are linked and which one you can safely share.
Published September 30, 2026 · 2 min read
A public address is a string of characters that tells the network where to send funds. You give it to whoever is paying you, much as you would give out an account number. Knowing your address lets someone send you coins, but it does not let them spend anything. That is why it is safe to hand out.
A private key is the secret that authorises spending from an address. Whoever holds the key can move the funds, and the network does not ask who they are. Because blockchain transfers are irreversible, nobody can bring back a transfer made with a stolen key. For this reason the key is never something to send in a chat, enter on a website someone linked you to, or hand to a supposed support agent.
The address is derived from the key, so each address has exactly one key behind it. The link works in one direction only: the key cannot be worked out from the address. That one-way relationship is what makes it safe to publish an address while keeping the key private. The table below sets the two side by side.
| Aspect | Public address | Private key |
|---|---|---|
| Purpose | Receiving funds | Authorising spending from the address |
| Can you share it? | Yes, it is safe to give out | Never |
| Relationship | Derived from the key | Cannot be worked out from the address |
| Everyday analogy | Like an account number | Like the secret that approves every payment |
| In a custodial wallet | You use it to deposit, through the app | Held by the service, not handled by you |
In a custodial wallet the service holds the key, so you work with addresses and the app rather than with the key itself. Nexus Pay is a wallet you open inside Telegram: you get deposit addresses for the coins and networks you use and manage everything through the app. The upside is that there is no secret for you to write down or lose. The trade-off is that your funds depend on the service and on how well you protect your own access to the app.
A deposit address is issued for one network. If you send a coin through a different network than the address was issued for, it will not arrive and cannot be reversed. In Nexus Pay, USDT and USDC can be deposited via TRC-20, ERC-20, BEP-20 and TON, while BTC and ETH use their own networks. Each network also has a minimum deposit amount shown in the app, and deposits below it are not credited. Check the address, the network and the minimum before you confirm.
A few habits cover most of the risk:
Nexus Pay offers an optional four-digit access code and lets you link a Google login as a second way in. It also keeps the main share of crypto funds in wallets without a permanent network connection. Whichever wallet you use, treat anything that unlocks your funds as a secret.
In Telegram, in a minute, with no paperwork.
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