Abstract: At present, the dynamic obfuscation strategy based on the Linear Feedback Shift Register (LFSR) and the test authorization strategy are the mainstream methods to protect the encryption chip from the threat of side scan-based attack. However, the LFSR seed or test authorization key stored in memory is extremely vulnerable to the attack on memory. To solve this problem, a dual dynamic obfuscation architecture is designed and a dual dynamic obfuscation strategy is constructed based on the two perspectives of side scan-based attack and memory attack. Among them, a dynamic obfuscation strategy of scan chain data based on LFSR self-update module is constructed to deal with side scan-based attack. Build an LFSR output sequence dynamic obfuscation strategy against memory attack. Experiments show that compared with the current secure scan strategy, the dual dynamic obfuscation strategy can protect the encryption chip from side scan-based attack and memory attack without affecting the testability of the chip. The area overhead is 0.31% when the LFSR self-update module number is 64 bits, and the number of XOR and XNOR gates in obviating logic gates are 8 bits each, it would needapplied at least 6.29×1018 test vectors for the attacker to brute force the dual dynamic obfuscation strategy.