为什么每个网站都应使用唯一密码

密码重复使用如何扩大损害

When one service leaks login data, attackers test the same email and password elsewhere. This automated practice is called credential stuffing. A reused password can expose unrelated accounts.

唯一凭据可限制泄露影响

If each site has a different password, a leak from one service does not directly reveal the credential for another. The email address may still be known, so multi-factor authentication remains valuable.

实现唯一性的三种方式

You can use a password manager, passkeys, or a deterministic method with a unique label per service. The method matters less than reliably avoiding reuse and maintaining recovery.

优先保护高价值账户

Email, banking, mobile carrier, cloud storage, and primary social accounts can be used to reset other services. Give these accounts unique credentials, strong second factors, and current recovery codes.

简单的重复使用审计

List your most important accounts without writing passwords. Mark where you suspect reuse, then change those credentials one at a time. Start with email and financial services.

Why small variations are not unique

Changing MyPassword1 to MyPassword2 does not create strong account separation. Attackers know users add site names, years, or incrementing numbers. Once one password is exposed, related variants become easier to predict.

A better approach

Use a password manager to generate independent random passwords, or use a carefully designed deterministic generator with account labels. In both cases, one service should not reveal the credential for another.

Prioritizing old accounts

1. Secure primary email accounts.
2. Secure banking and payment services.
3. Secure mobile-provider and cloud-storage accounts.
4. Replace reused credentials on shopping and social accounts.
5. Close accounts you no longer need.

Conclusion

Unique passwords limit breach damage. The goal is not cosmetic variation; it is independent account credentials supported by strong recovery and multi-factor authentication.