Verifying Security Settings

You may want to verify that your Titanium FPGA is correctly using the security features that you enabled. You can use the Advanced Device Configuration Status dialog box (Programmer) to view the security status signals. See Configuration Status Register for details.

Note: With the AES encryption feature enabled, Titanium FPGAs accept both encrypted and unencrypted bitstreams as valid. So you can configure the FPGA with a plaintext bitstream even after you blow its fuses with an AES key.

Conversely, if you have blown fuses for RSA authentication, the FPGA only accepts a bitstream signed with the private key you blew into the fuses.

Figure 1. Advanced Device Configuration Status Security Signals

You can also test out the bitstream security features by trying to program the FPGA with a bitstream that you signed with the wrong RSA key, an unsigned bitstream, or a bitstream encrypted with the wrong key. If the Titanium FPGA detects a key mismatch, it will not go into user mode.