Background introduction: Tencent’s CNB platform only supports WeChat login, with no conventional email account method, leading to several guys in the group complaining about it daily – it’s getting annoying. The Tencent product manager came up with a compromise solution: support Passkey login.

Every day, we are repeating a dangerous action: entering passwords. Despite our complex rules (uppercase, special symbols, numbers), data breaches, phishing attacks, and the frustration of “forgotten password” issues continue to trouble everyone.

Tech giants (Apple, Google, Microsoft) along with the FIDO Alliance have provided the ultimate solution: Passkey (Passcode Key). It’s not just a “replacement” for passwords; it completely “eliminates” them.

The login process has shifted from verifying passwords to verifying the current device’s trustworthiness.

Explain how Passkey works, how it can be used for login management, collect relevant content, and output an article for internet publication

What is a Passkey?

Simply put, a Passkey is a digital credential stored on your device. It replaces the traditional “username + password.” When you log into websites that support Passkeys (such as Google, GitHub, Adobe), you don’t need to enter any characters – you just verify using facial recognition (Face ID), fingerprint (Touch ID), or device PIN, and you’re instantly logged in.

Key Difference: A password is a string of characters you remember (easily stolen, guessed, or forgotten); a Passkey is an asset you own – an encrypted key stored within the device hardware.

How Passkeys Work: Asymmetric Encryption

Passkey is built on the WebAuthn standard and the FIDO2 protocol. To understand it, we need to understand Public Key Cryptography.

Imagine a passkey as a pair of “keys” and “locks”:

1. Private Key:

   • Where is it stored? Securely stored on your device (such as iPhone’s secure enclave, computer’s TPM module, or password manager).
   • Characteristics: Extremely sensitive, never sent to the server, and doesn’t leave your device.
   • Function: It’s your “digital signature pen.”

2. Public Key:

   • Where is it stored? Uploaded and stored on the website/app’s server.
   • Characteristics: Publicly visible, not sensitive.
   • Function: It’s used to verify your signature – like a “money checker.”

Handshake Details (The Process)

When you log in using a Passkey, a sophisticated “challenge-response” mechanism takes place:

1. Initiate Login: You click “Login,” and the website server sends a random mathematical problem (Challenge) to your device.

2. Local Verification: Your phone/computer displays a prompt requesting you unlock it using biometrics (face recognition/fingerprint).

   • Note: This step is solely for authorizing the device to use its private key; biometric data itself is not uploaded.

3. Digital Signature: Upon successful unlocking, the device uses its private key to “sign” the mathematical problem and sends the signature result back to the server.

4. Server Verification: The server uses the public key you previously provided to verify this signature. If it’s valid, the server confirms that “the person who has validated the key indeed holds the private key,” thereby allowing login.

Why Passkeys Are Significantly More Secure Than Passwords?

Passkeys address the three major pain points of traditional passwords:

Completely Immune to “Phishing Attacks” (Anti-Phishing)

This is the most robust feature of Passkey. The Passkey protocol enforces the inclusion of Origin Binding.

• Scenario: A hacker creates a fake g00gle.com to trick you into logging in.
• Result: Your browser and system will detect that the current domain does not match the domain registered for your Passkey, google.com, and refuse to initiate authentication. You don’t even have a chance to “fall for it” and enter your password.

Server Leak Was Useless

Even if hackers breached Google’s servers and stole all the databases, they would only have obtained the public key.

The public key cannot be used to derive the private key. Holding the public key is like holding a lock; but without the key (the private key which resides on your phone), the hacker couldn’t access your account.

No “Weak Passwords”

Users no longer need to set weak passwords like “123456,” as the keys are strong, encrypted data generated by algorithms.

How Passkeys Are Changing “Login Management”?

Previously, we relied on tools like 1Password, LastPass, or Chrome browser to store lengthy strings of characters. Now, login management is undergoing a fundamental shift.

Cross-Device Sync (Passkey Sync)

Early hardware keys (such as YubiKeys) are easily lost. Current Passkeys support cloud synchronization:

• Apple Ecosystem: Through iCloud Keychain sync. Passkeys you create on your iPhone are automatically available on your Mac.
• Google Ecosystem: Through Google Password Manager sync for Android and Chrome.
• Third-Party Management: Tools like 1Password, Dashlane, etc., fully support Passkey. This means you can seamlessly sign in across ecosystems (using a Passkey stored in your iPhone on a Windows computer).

Cross-Device Login (via QR Code)

What do you do if you want to log in to a PC at an internet cafe (Windows) but your Passkey is on your iPhone?

1. Select “Login via Another Device” on the web page.
2. A QR code (FIDO Cross-Device Flow) appears on the screen.
3. Use your iPhone’s camera to scan the QR code.
4. Your phone establishes a Near Field Connection with the computer via Bluetooth (to verify you are present) and performs biometric authentication.
5. Login is successful on the PC.

From “Managing Secrets” to “Managing Trust”

Future login management will no longer be about checking individual plaintext passwords, but rather managing trusted devices.

• You can see: “My GitHub account is bound to my iPhone and MacBook.”

• If your phone is lost or stolen, you simply revoke the device’s public key access rights from the server (or cloud account).

Table Comparison: Password vs. Passkey

Table Comparison: Passwords vs. Passkeys

Table Comparison: Passwords vs. Passkeys

Table Comparison: Password vs. Passkey

Table Comparison: Password vs. Passkey

Current Challenges and Future

Despite the great potential of Passkeys, widespread adoption still requires time:

• Platform Barriers: While standards are unified, Apple, Google, and Microsoft offer the smoothest experiences within their respective ecosystems. Cross-ecosystem transitions (such as an Android phone paired with an iPad) are feasible but still involve some friction.
• Device Dependency: Losing all trusted devices without a cloud backup can make account recovery difficult (typically requiring a backup recovery code).
• Legacy System Compatibility: Many older websites and internal corporate networks do not yet support the WebAuthn standard.

Summary

Passkey isn’t an upgrade to passwords; it’s a fundamental reconstruction of internet identity verification. It leverages modern device biometric capabilities and public-key cryptography, elevating security to a financial level while simplifying the user experience to the extreme.

For average users, enabling Passkeys on supported platforms (Google, Apple, Microsoft, Amazon, etc.) is the highest return on investment for improving personal digital security.