Serial Number to Base36 Converter

This tool transforms sequential integers (e.g., database IDs like 1, 2, 3) into short, non-sequential alphanumeric strings (e.g., 3f, m9, x2). Unlike standard Base36 conversion which remains sequential, this tool uses a position-dependent bijective mapping (the Shrti algorithm) to shuffle the character set at every digit position.

Using sequential IDs in public URLs (e.g., /user/1050) exposes your business growth metrics to competitors (the German Tank Problem) and allows scrapers to easily iterate through your data. Obfuscating these IDs into random-looking strings protects your data integrity while remaining fully reversible without a database lookup.

The encoding process treats the number as a Base36 integer, but instead of using the standard alphabet 0-9a-z, it selects a character from a specific randomized alphabet based on the digit's position i.

Where d is the Base36 digit vector of the input number N, and Map_i is the shuffled alphabet for position i.