Crypto
2 min read

Wallet Address

A public identifier derived from a wallet’s public key, used to receive cryptocurrency. Addresses are safe to share publicly; only the corresponding private key can authorize spending from them.

What an address is

The technical reality:

  • Public identifier derived from the public key.
  • Used to receive funds.
  • Visible on-chain — anyone can see all activity.
  • Not directly revealing of identity (pseudonymous).
  • One wallet can have many addresses.

Addresses are like account numbers for blockchain accounts.

Address formats

Different chains use different formats:

  • Ethereum / EVM — 0x followed by 40 hex characters.
  • Bitcoin — multiple formats: legacy (1...), SegWit (3...), bech32 (bc1...).
  • Solana — base58 encoded, ~44 characters.
  • ENS names — human-readable like vitalik.eth.

Sending to wrong format typically fails or loses funds.

How addresses work

Mechanics:

  • Generated from public key via cryptographic hash.
  • Public key generated from private key.
  • One private key can generate many addresses (HD wallets).
  • Address itself can't be reversed to private key.

The math underlying this is well-established cryptography.

Common address mistakes

Major errors:

  • Wrong network — sending ETH to a BTC address (or vice-versa) loses funds.
  • Wrong chain — sending USDC on Ethereum to Solana USDC address loses funds.
  • Typo — even one wrong character means lost funds.
  • Trusted contact spoofing — malicious actors switch addresses in clipboard or messages.

Always verify addresses carefully before sending.

Address verification

Best practices:

  • Copy and paste — don't type addresses.
  • Verify first and last several characters — checksum-like check.
  • Test transaction — send small amount first for new addresses.
  • Use ENS or address book — for repeat recipients.
  • Hardware wallet display — verify address on device, not just screen.

These practices prevent the most-common loss scenarios.

Privacy considerations

Addresses are pseudonymous:

  • All transactions visible on-chain.
  • Address clustering — analysis can link addresses to same owner.
  • KYC linkage — exchange withdrawals connect address to identity.
  • Privacy practice — use new addresses for receiving when possible.
  • Privacy coins — provide stronger privacy.

Standard wallets don't provide much privacy at scale.

Common patterns:

  • Address poisoning — sending tiny amount from spoofed address to appear in history.
  • Clipboard malware — replaces copied addresses with attacker's.
  • Fake support — asks for address to "fix" issues then sends scams to it.
  • Lookalike addresses — first/last characters match real address.

Sophisticated address-based attacks are common.

What individuals should know

For all users:

  • Verify addresses carefully every time.
  • Match network and chain to the address format.
  • Test with small amounts for new addresses.
  • ENS names reduce typo risk.
  • Hardware-display verification for important transactions.

Wallet addresses are the routing layer of crypto. Understanding their format, verification, and risks is essential to safe transactions.