The product does not adequately protect confidential information on the device from being accessed by Outsourced Semiconductor Assembly and Test (OSAT) vendors.
In contrast to complete vertical integration of architecting, designing, manufacturing, assembling, and testing chips all within a single organization, an organization can choose to simply architect and design a chip before outsourcing the rest of the process to OSAT entities (e.g., external foundries and test houses). In the latter example, the device enters an OSAT facility in a much more vulnerable pre-production stage where many debug and test modes are accessible. Therefore, the chipmaker must place a certain level of trust with the OSAT. To counter this, the chipmaker often requires the OSAT partner to enter into restrictive non-disclosure agreements (NDAs). Nonetheless, OSAT vendors likely have many customers, which increases the risk of accidental sharing of information. There may also be a security vulnerability in the information technology (IT) system of the OSAT facility. Alternatively, a malicious insider at the OSAT facility may carry out an insider attack. Considering these factors, it behooves the chipmaker to minimize any confidential information in the device that may be accessible to the OSAT vendor. Logic errors during design or synthesis could misconfigure the interconnection of the debug components, which could provide improper authorization to sensitive information.
- Ensure that when an OSAT vendor is allowed to access test interfaces necessary for preproduction and returned parts, the vendor only pulls the minimal information necessary. Also, architect the product in such a way that, when an "unlock device" request comes, it only unlocks that specific part and not all the parts for that product line. - Ensure that the product's non-volatile memory (NVM) is scrubbed of all confidential information and secrets before handing it over to an OSAT. - Arrange to secure all communication between an OSAT facility and the chipmaker.
Effectiveness: Moderate
The impact depends on the confidential information itself and who is inadvertently granted access. For example, if the confidential information is a key that can unlock all the parts of a generation, the impact could be severe.
Appropriate Post-Si tests should be carried out to ensure that residual confidential information is not left on parts leaving one facility for another facility.
Effectiveness: High
Appropriate Post-Si tests should be carried out to ensure that residual confidential information is not left on parts leaving one facility for another facility.
Effectiveness: Moderate