保護Soft-IP的資訊隱藏技術

Abstract

由於近年來電腦輔助設計軟體和超大型積體電路製程的進步，產品從研發到推出市場的時間愈來愈短。為了因應急劇縮短的研發時間，必須重複使用事先設計好的元件。因此在這種情況下，創造了一個新的商機——販售事先經過設計且能夠重複使用的元件(即矽智財、Intellectual Property)。但是這個市場必須要有保護的機制以避免IP被惡意的濫用或是轉售。在本論文中，我們提出一個藉由在有限狀態機中隱藏資訊以保護Soft-IP的新方法。這個方法將有限狀態機中的State重新編碼，使得在特定路徑上相鄰兩個State編碼的差值即為所要隱藏的資訊。經過分析發現，我們的方法具有難以被查覺、難以被篡改，以及難以被假造的特性，並且利用Scan-Chain即可檢測在特定電路中是否有隱藏資訊。我們用我們的方法將8個8bit的資訊隱藏在UART Receiver電路中，得到的結果顯示，這些電路不僅仍然正常運作，而且只用原來的State就能隱藏資訊。

As the progress of EDA tools and manufacturing technologies, we get shorter and shorter time-to-market. In order to catch up with the decreasing time-to-market, reuse pre-defined and pre-verified components is inevitable. This creates a new market of selling reusable pre-defined components ( i.e. Intellectual Property ). But the IP must be protected by some techniques from malicious duplication. In this thesis, we propose a new method to protect Soft-IP by hiding information in FSMs. We re-encode the state coding in the way that the difference of two states of selected edge in a specific path is equal to the information we want to hide. Through analysis, we found our method has the property of hard to be observed, hard to be removed, and hard to be faked. Using scan-chain, we can detect whether a specific FSM hides our information or not. We hide eight 8-bit information data in a UART receiver using our method. The result shows that the UART receiver works correctly and we can hide the eight 8-bit information in it without adding new states.