This Year’s Holiday Puzzle: Find The Trojan Horse

The challenge reflects real-world problem of trust in hardware designs.


The term “Trojan horse” is widely used, but it’s likely that not everyone knows the story behind this metaphor. It refers to an ancient legend about a giant wooden horse that contained a most unpleasant surprise for its recipients. In general usage, the term refers to anything dangerous that lurks within a seemingly innocent disguise. The electronics hardware design community is increasingly worried about Trojan horses that might be hiding within an IP or SoC design. Security risks of a malicious agent exploiting an unintended design vulnerability are bad enough, but the specter of a deliberate Trojan is even scarier. A hardware Trojan is engineered to cause major damage in response to a trigger known by the attacker. It could expose “secure” data, cause serious product malfunction, or even destroy a chip.

Establishing trust in a hardware design includes detecting and eliminating any Trojan horses inserted anywhere in the development process. For this year’s annual holiday puzzle, we’re asking you to find the Trojans in two RTL designs. As always, we have some cool prizes for those who submit the best solutions. For more background on the original Trojan horse, details on the holiday puzzle, and entry instructions, please visit

Have fun, and best of luck!

Leave a Reply

(Note: This name will be displayed publicly)