How to Protect Your Customers’ Data with a Secure Form

A data breach can be costly. In 2024, the average cost of a data breach was $4.45 million according to IBM. For small and medium French businesses, the impact is often fatal: 60% of them close within 6 months following a cyberattack.

Data collection through your forms represents a critical entry point. Email, name, phone, sometimes banking information: each piece of information transmitted by your customers deserves maximum protection with a secure form.

This guide concretely explains how to secure your contact forms and protect your customers’ data.

Why Form Security Has Become Critical

Current Threats to Web Forms

Cybercriminals particularly target forms for several reasons:

• SQL injection: exploiting vulnerabilities to access your database
• Cross-Site Scripting (XSS): injecting malicious scripts via form fields
• Data interception: capturing information in transit on unsecured connections
• Brute force attacks: massive attempts to access accounts or systems

In France, CNIL recorded 5,037 data breach notifications in 2023. A 14% increase compared to the previous year.

Consequences of a Security Breach

A security breach on your forms leads to:

• GDPR sanctions: up to 20 million euros or 4% of annual revenue
• Loss of trust: 65% of customers leave a company after a data leak
• Remediation costs: audit, notification, corrective measures
• Image damage: permanently tarnished reputation

The Fundamentals of a Secure Form

HTTPS Encryption: The Essential Foundation

Every form must be served via HTTPS. This protocol encrypts data between the user’s browser and your server.

Without HTTPS:

• Data travels in clear text over the network
• Anyone on the same network can intercept it
• Browsers display a “Not Secure” warning

Verify that your SSL/TLS certificate is:

• Valid and not expired
• Issued by a recognized authority
• Configured to force HTTP to HTTPS redirect

Server-Side Data Validation

Never trust incoming data. Client-side validation (JavaScript) can be bypassed. Your server must systematically:

• Verify format: valid email, consistent phone number
• Limit length: avoid buffer overflow attacks
• Escape special characters: neutralize injection attempts
• Filter malicious content: scripts, unauthorized HTML tags

Secure Data Storage

Once collected, your data must be stored with care:

• Encryption at rest: data is unreadable without the decryption key
• Restricted access: only authorized persons can view the data
• Logging: traceability of all access and modifications
• Encrypted backups: protection of backup copies

How to Secure a Form: Practical Guide

1. Use Anti-CSRF Tokens

CSRF (Cross-Site Request Forgery) attacks exploit a user’s session to submit forms without their knowledge.

The anti-CSRF token works as follows:

1. The server generates a unique token for each session
2. This token is included in the form (hidden field)
3. On submission, the server verifies the match
4. Any submission without a valid token is rejected

This protection blocks malicious requests from other sites.

2. Implement a Robust Password Policy

If your form creates user accounts, require strong passwords:

• Minimum 12 characters
• Combination of uppercase, lowercase, numbers, special characters
• No dictionary words or personal information
• Verification against compromised password databases (Have I Been Pwned)

Server-side, store only the password hash with a modern algorithm (bcrypt, Argon2).

3. Limit Submission Attempts

Rate limiting protects against brute force attacks and spam:

• Maximum 5 submissions per IP every 10 minutes
• Temporary block after exceeding
• Alert for suspicious behavior

This simple measure stops 90% of automated attacks.

4. Minimize Collected Data

The principle of minimization is at the heart of GDPR. Only ask for strictly necessary information.

Questions to ask yourself:

• Do I really need the phone number?
• Is the postal address essential?
• Does the date of birth add value?

The less data you collect, the less you expose your customers in case of a leak.

GDPR Compliance: Legally Protecting Your Customers’ Data

Data Controller Obligations

As a data collector, you must:

• Inform: clearly explain why you’re collecting this data
• Obtain consent: unchecked checkbox for marketing communications
• Secure: implement appropriate technical measures
• Document: maintain a processing register
• Notify: report any breach to CNIL within 72 hours

Mandatory Notices on Your Form

Your form must display:

• The identity of the data controller
• The purpose of collection
• The mandatory or optional nature of each field
• Data recipients
• Retention period
• User rights (access, rectification, deletion)
• A link to your privacy policy

Example of Compliant Notice

“The information collected is subject to computer processing intended for [purpose]. In accordance with GDPR, you have the right to access, rectify, and delete your data. To exercise this right, contact [email]. See our [privacy policy].”

With Skedox, these notices are integrated by default into your forms. You remain compliant without configuration effort.

Mistakes That Compromise Your Forms’ Security

Mistake #1: Storing Data in Plain Text

Storing emails, phones, or addresses without encryption is a serious fault. In case of intrusion, all your customer data is exposed.

Solution: enable encryption at rest on your database.

Mistake #2: Lack of Logging

Without logs, it’s impossible to detect an intrusion or understand the origin of a leak.

Solution: record every data access with timestamp and user identification.

Mistake #3: Overly Broad Permissions

When everyone has access to everything, the risk of internal leaks explodes. 34% of data breaches involve an internal actor.

Solution: apply the principle of least privilege. Each employee only accesses data necessary for their function.

Mistake #4: Neglecting Updates

Security vulnerabilities are regularly patched. An outdated CMS or plugin becomes an entry point for attackers.

Solution: automate security updates or use a hosted solution that handles this for you.

Security Checklist for Your Forms

Before putting a form into production, verify these points:

Infrastructure:

• Valid SSL/TLS certificate and forced HTTPS
• Server up to date with latest patches
• Web application firewall (WAF) configured

Code:

• Server-side data validation
• Active CSRF protection
• Special character escaping
• Rate limiting configured

Data:

• Encryption at rest
• Restricted and logged access
• Defined retention policy
• Encrypted and tested backups

Compliance:

• Legal notices present
• Explicit consent for marketing
• Rights management procedure in place
• Processing register up to date

The Simple Solution: Outsource Security

Implementing all these measures in-house requires time and skills. For an SME, it’s rarely cost-effective.

Skedox allows you to create secure forms in minutes. The platform natively integrates:

• HTTPS and at-rest encryption
• Anti-CSRF and anti-spam protection
• GDPR compliance by default
• Data hosting in Europe
• Complete access logging

You focus on your business. Security is handled by experts.

How to Concretely Protect Your Customers’ Data

Immediate Action Plan

Week 1: Audit

• List all your existing forms
• Identify collected data
• Verify security measures in place

Week 2: Priority Corrections

• Enable HTTPS everywhere
• Add missing GDPR notices
• Remove unnecessary fields

Week 3: Reinforcement

• Implement rate limiting
• Configure logging
• Restrict internal access

The Quick Option

If you lack time or technical resources, migrate to a specialized solution. Try Skedox for free and create your first secure form in less than 5 minutes.

Conclusion: Protecting Customer Data Is No Longer Optional

Your forms’ security is a legal responsibility and a commitment to your customers. Each piece of collected data deserves protection matching the trust placed in you.

A secure form relies on:

• End-to-end encryption (transit and rest)
• Rigorous data validation
• Native GDPR compliance
• Controlled and logged access
• Regular updates

Companies that invest in their forms’ security see a 27% increase in conversion rate. The reason is simple: users trust sites that protect their information.

Don’t leave your customers’ security to chance. Discover Skedox and create forms that inspire trust today.