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edfas.org 29 ELECTRONIC DEV ICE FA I LURE ANALYSIS | VOLUME 24 NO . 2 be huge during conflict and war. This may allow attackers control over themost sensitive devices performing critical applications. Similarly, inadvancedpackaging, interposer serves as a microcarrier formounting chips andprovides highdensity and high bandwidth interconnections. The architecture of interposer-based advance packaging has improved the complexity of input-output interconnects that are suitable targets for attackers to manipulate the design and fabrication parameters to breach sensitive long-term access infrastructures. It would be possible to use such backdoor access to cripple a corporation or a country. First, it was important to gain a thorough understanding of the product concept, exploit the design and process parameters during fabrication, and ensure that the com- promised products entered the correct locations to carry out such a large-scale attack. The attack outlined in the Big Hack articlewas detected and tackled relatively early. Not only did the Big Hack type attack take years of vision, but it also needed a profound knowledge of the design process of the target. The impact on vital infrastructures of such an elaborate attack may have been much worse. It is therefore essential to analyze the advanced packag- ing supply chain and its weaknesses carefully. A detailed analysis of vulnerabilities in the fabrication process of interposer has been discussed in the following section. VULNERABILITIES IN THE FABRICATION PROCESS AND SUPPLY CHAIN An interposer is an important asset for advanced packaging, and it is crucial to understand the supply chain model well and the potential adversaries in the fabrication process to assess its vulnerability. This section focuses on the fabrication aspect of the interposer to assess the potential areas of malicious changes that could be com- promised during the fabrication process. ADVANCED PACKAGING SUPPLY CHAIN The new industrymodel of advancedpackagingdesign andmanufacturing encourages comprehensive outsourc- ing and inclusion in the package lifecycle of untrusted components and organizations to minimize production costs and reduce time to market. Outsourced advanced packaging steps have introduced various supply chain vulnerabilities and risks. A brief overview of the current stages in the advanced packaging supply chain and the detailed assessment of potential vulnerabilities that may be added at each fabrication stage is shown in Fig. 5. An untrusted foundry or rogue employee from the trusted foundries will leverage these vulnerabilities at any time during the interposer manufacturing phase to change the TSVs, RDLs and UBMs. Attacks such as IP piracy, inser- tion of Trojans, cloning, and overproductionmay provide adversaries with backdoor access to launch a stealthy attack or trigger service denial. As the supply chain has opened up to third-party companies worldwide, original equipment manufacturers (OEMs) have also lost leverage over themanufacture of the interposer. Thus, in the supply chain, manufacturing assurance is a challenging task. The foundries are inexorably multinational, and the security and durability of the final product could be subverted by everyone involved in the process. This article concentrates Fig. 5 Interposer fabrication vulnerabilities in the supply chain of advanced packaging.