Phantom materializes ‘sign in with Solana’ wallet authentication
Phantom said it collaborated with Solana Labs to make the method compatible with Solana’s wallet standard, while also providing support for others within the ecosystem

Skorzewiak/Shutterstock, modified by Blockworks
Wallet service provider Phantom said Monday it has introduced a new feature allowing applications to authenticate users using a Solana address.
The introduction of Sign In With Solana (SIWS) is intended to improve the user experience and security by streamlining the traditional “connect” and “signMessage” flow into a single-click “signIn” method.
Traditionally, the connect function enables a user’s digital wallet to interact with an application, while “signMessage” allows the user to cryptographically verify their identity.
The message lacks human-readable information, which can sometimes lead to new and seasoned users agreeing to malicious prompts.
Even in cases when connecting a wallet to trusted applications, unexpected pop-up signatures can often confuse or frighten new users, Phantom said in a statement. This, in turn, can often be a major hurdle for new entrants, it said.
The one-click sign-in method, available as of Phantom version 23.11, allows Solana developers to prompt users to connect and sign a standardized authentication message and prove ownership of their addresses.
Designed as a drop-in replacement for the previous two-step authentication flow, the sign-in method also provides developers with a robust API for creating standardized authentication messages, Phantom said.
The responsibility for message construction shifts from applications to the wallet, allowing Phantom to scrutinize elements such as the site’s domain or the time of message issuance to ensure legitimacy.
It is unclear whether there could be fresh privacy concerns associated with the shift of responsibility in message construction. Blockworks has reached out to Phantom for comment.
In some instances, that construction may help slow or hinder the progress of malicious actors. That could help prevent instances like last year’s breach, when a coding error allowed hackers to easily find and use client passwords, leading to a breach in both Slope and Phantom wallets.
Private keys associated with the impacted wallets were either leaked or compromised, and these keys were then utilized to authorize fraudulent transactions, according to reports at the time.
The sign-in feature released on Monday makes authentication more consistent and allows Phantom to check for suspicious activity, its developers said.
Ethereum dapps similarly can facilitate a “sign in with Ethereum” feature using Ethereum Name Service (ENS), as part of a push for decentralized identity services.
Get the news in your inbox. Explore Blockworks newsletters:
- Blockworks Daily: The newsletter that helps thousands of investors understand crypto and the markets, by Byron Gilliam.
- Empire: Start your morning with the top news and analysis to inform your day in crypto.
- Forward Guidance: Reporting and analysis on the growing intersection of crypto and macroeconomics, policy and finance.
- 0xResearch: Alpha directly in your inbox. Market highlights, data, degen trade ideas, governance updates, token performance and more.
- Lightspeed: Built for Solana investors, developers and community members. The latest from one of crypto’s hottest networks.
- The Drop: For crypto collectors and traders, covering apps, games, memes and more.
- Supply Shock: Tracking Bitcoin’s rise from internet plaything worth less than a penny to global phenomenon disrupting money as we know it.