Sign In With Solana (SIWS): the signature login

Sign In With Solana is a login where your wallet signs a text message. What it signs, why nothing goes on-chain, and what Cherry builds from it.

Sign In With Solana (SIWS) is a login in which your wallet signs a short piece of text to prove that an address belongs to you. Nothing is written to the blockchain and no gas is paid. Cherry (cherry.fun) is a wallet-to-wallet messenger and community app for crypto that signs people in this way, so the wallet is the entire account: no phone number, no email, no password.

How Sign In With Solana works

The site asks, the wallet writes the text, you approve it. The message names the site making the request, the address doing the signing, a line of plain text explaining the request, and a one-time nonce so an old signature cannot be replayed later. Because the wallet composes the message, it can check that the site in front of you is the site named inside it, which is the part that catches a copycat login page.

The idea started on Ethereum. ERC-4361, Sign-In with Ethereum, is a final standard that describes how accounts “authenticate with off-chain services by signing a standard message format”. Sign In With Solana, the specification Phantom maintains, is modelled on it and shifts the writing of the message from the site to the wallet. On what approving one costs you, that specification is blunt: “This request will not trigger any blockchain transaction or cost any gas fee.”

Message signature or transaction signature

One word, sign, covers two very different acts.

QuestionMessage signatureTransaction signature
What it doesProves an address is yoursMoves tokens or changes on-chain state
Goes on-chainNoYes
Costs gasNoYes
Can it spend your balanceNoYes
Where you meet itLogins, profile claimsSwaps, transfers, mints, spend approvals

Phantom’s developer documentation says the same thing about the left-hand column: “Message signatures do not involve network fees and are a convenient way for apps to verify ownership of an address.” Read the text anyway. A signature cannot spend your balance, but whoever collects it can open a session in your name with it.

Wallets that sign you in on Cherry

Phantom, Solflare and Backpack sign the message in the browser extension or inside their own app. On the Solana Seeker phone, the Seed Vault Wallet does it through Mobile Wallet Adapter , the Android handoff that lets an app ask the wallet on the same phone for a signature.

Example on Cherry

Pick a wallet in the Cherry web app and the button reads “Sign in with Phantom”, or whichever one you picked. Cherry then asks you to “Sign a message with your wallet to verify ownership and start your session.” One approval later the app is open.

That signature does more than start a session. Cherry derives your encrypted identity from it, which is what makes direct messages end-to-end encrypted: the keys come from your wallet and the private key never leaves it. Your display name is a name you own, a .sol, .sns or .skr, and your address is your profile. Cherry hosts 200+ communities as of September 2026, and none of them collects an email to let you in.

Two limits are worth saying out loud. Lose the wallet and you lose the account, because there is no password to reset and no support desk that can hand it back; your seed phrase, or the phone holding it, is the backup. And group chats are not end-to-end encrypted, by design, so moderation and bots can work.

FAQ

Is signing a message to log in safe?

Yes, as long as you read it first. A message signature proves you control an address and cannot move tokens, pay gas, or approve a spend. The risk sits with the site: a copycat page can use the signature you hand it to open a session in your name, so sign in only where you opened the page yourself.

Sources

Try Cherry

Sign in with a wallet, DM any address, and join token-gated and paid communities. No phone number, email, or KYC.