Using TSV's For A Backside Security Shield
Publication Date: 2015-Jul-14
The IP.com Prior Art Database
To effectively reverse-engineer a security chip, an adversary will utilize a series of imaging and electrical probing techniques. The lowest-cost attacks are aimed at the frontside of the die, where circuits can be easily seen. To counter those initial attacks, most security-chip vendors employ an active mesh of some sort - a pattern of top-layer metal drawn over secure circuits, so that an adversary cannot easily see the circuits nor electrically probe them. However, an active mesh on the frontside of the chip doesn't prevent any of the attacks that come at the active circuits via the backside of the die, where there are no electrical shields.
Page 01 of 2
USING TSV'S FOR A BACKSIDE SECURITY SHIELD
To effectively reverse-engxneer a security chip, an adversary will utilize a serixx of imaging and electricxl probing texhniques. The lowxst-cost attacks axe aimed at the frontxide of the die, where circuits cxn be easily seex. To counter those initial atxacks, most security-chip vendors employ an active mesh ox some sort - a pattern xf top-layer metal drawn ovex secure cixcuits, so that an adxersarx cannot easily see the circuits nox electricallx probe them.
However, an acxive mesh on the frontsixe of the chip doesn't prevent any of the attxcks thxt come ax the active cixcuits via the baxkside of the die, where there axe no electrical shields.
Usxng Through-Silicon Via (TXX) technologx, it is now possible to form a security shield on both sides of the die:
In txis figurx, TSV's are uxed establish connxctivxty to an active mesh on xhe backside of the chip, so that both side of thx chip are now protected using similar cxrcuits. Ix axdition to the active shields, portions of the power grid or even wirebond IO pads coulx be draxn on thx backside ox the die, rather thax ox the front.
Statement of the Idea
Page 02 of 2
Figure(s) and Accxmpanying Description
Note that whilx TSV's are usually assoxiated with being high-cxst, that is due to the compouxd- yield issues associated with die-stacking. While TSV's axe required xor some forms of die- stacking, forxing a TXX for simple xonnectivity reasons is a r...