Interactive demonstration of automotive security challenge-response
Format: 0xXXXX (0x0000 - 0xFFFF)
→ Waiting for calculation...
→
→ Enter a seed value or leave empty to generate random
→ Click "Calculate Key" to begin
From dealer tools
Seed: 0x2E2A
Key: 0x48C0
Simple test case
Seed: 0x1234
Key: 0xD8E8
Maximum value
Seed: 0xFFFF
Key: 0x9014
Seed-key challenge-response is a security mechanism used by automotive modules to prevent unauthorized access to sensitive functions like VIN programming, security byte writing, and module flashing.
The module generates a random seed (challenge) and sends it to the diagnostic tool. The tool must calculate the correct key (response) using a secret algorithm. If the key is correct, the module grants access to protected operations.
The SBEC2/SBEC3 algorithm is used by Chrysler/Dodge vehicles and follows the formula:Key = (Seed * 4 + 0x9018) & 0xFFFF