Day 11 Enhancing Frontend Security: Client Storage Best Practices

Today, on Day 11 of my frontend system design journey, I'm diving into Client Storage Security. In a landscape where data breaches are prevalent, protecting sensitive client-side information is imperative for developers.

Let's dive into the key considerations and best practices:

Storing Sensitive Data on Client Storage

1. Whenever possible, opt for server-side storage for sensitive data to minimize the risk of exposure.
2. If client storage is necessary, employ robust encryption algorithms to encode the data, ensuring it remains protected even if accessed illicitly.
3. Implement token expiry mechanisms to limit the window of vulnerability.

Authentication

1. Utilize industry-standard authentication protocols such as JWT (JSON Web Tokens) or OAuth to authenticate users securely.
2. Enforce session token expiry to mitigate the risk of session hijacking.
3. Consider implementing multi-factor authentication for an added layer of security.

Data Integrity

1. Encryption is key to maintaining data integrity. Ensure that sensitive data is encrypted both in transit and at rest.
2. Implement checksums to detect any unauthorized alterations to the data.

Storage Limits

Be mindful of storage limitations across different client-side storage mechanisms

• LocalStorage: Aim to store 5 to 10 items per domain.
• Session Storage: Limit storage to 5 to 10 MB.
• IndexedDB: Typically allows for larger storage, ranging from 50 MB to 100 MB.
• Cookies: Keep cookie sizes between 4 KB to 20 KB.
• Cache: Utilize cache judiciously, typically capped at around 100 MB.

Note that these limits may vary depending on the browser used.

Session Management

When managing sessions, set cookies with the 'HttpOnly' and 'Secure' flags to prevent client-side scripts from accessing sensitive session cookies.

By adhering to these best practices, developers can significantly enhance the security posture of their frontend applications. Remember, security is not a one-time effort but an ongoing commitment. Stay vigilant, stay informed, and keep elevating your frontend skills. Together, we can build a safer digital world.