What is Format Preserving Encryption (FPE)?

Format Preserving Encryption (FPE) is a cryptographic technique that encrypts data while maintaining its original format. In our ID Generator, it converts 4-digit numbers to 3-letter codes deterministically, ensuring the same input always produces the same output with a given key.

Is the encryption collision-free?

Yes, our FPE implementation is 100% collision-free. Each 4-digit number (0000-9999) maps to exactly one unique 3-letter code (AAA-ZZZ), and vice versa. This 1:1 mapping ensures no two different numbers will ever produce the same code.

How does the encryption key work?

The encryption key determines how numbers are mapped to codes. The same key always produces the same encryption mapping. By default, the current year is used as the key, but you can use any custom key. To decrypt a code, you must use the same key that was used for encryption.

Is my data secure and private?

Absolutely. All encryption and decryption happens entirely in your browser using client-side JavaScript. Your data never leaves your device, and no information is sent to any server. The encrypted codes are designed so that the original numbers cannot be deduced without the encryption key.

What are common use cases for ID encryption?

ID encryption is commonly used for customer IDs, order numbers, invoice numbers, and any sensitive numeric identifiers where you need privacy protection, GDPR compliance, or want to prevent sequential ID guessing while maintaining a readable format.

ID Generator

Generate encrypted 3-letter code from 4-digit number.

How it works

Converts 4-digit numbers (0000-9999) to 3-letter codes (AAA-ZZZ)
Absolutely collision-free with deterministic 1:1 mapping
Key is automatically set to current year (can be modified)
Original values cannot be deduced from encrypted codes

Encrypt

Decrypt

Example

Input: 1234 with key 2025

Output: ??? (depends on encryption key)

* Same input with same key always produces the same output