신뢰성 향상을 위한 듀얼 안티퓨즈 OTP 메모리 채택 D-PUF 회로

김승열,이제훈,Kim, Seung Youl,Lee, Je Hoon 한국융합보안학회 2015 융합보안 논문지 Vol.15 No.3_2

A typical SRAM-based PUF is used in random number generation and key exchange process. The generated out puts should be preserved, but the values are changed owing to the external environment. This paper presents a new D-PUF logic employing a dual anti-fuse OTP memory to the SRAM-based PUF. The proposed PUF can enhance the reliability of the logic since it can preserve the output values. First, we construct the OTP memory using an anti-fuse. After power up, a SRAM generates the random values owing to the mismatch of cross coupled inverter pair. The generated random values are programed in the proposed anti-fuse ROM. The values that were programed in the ROM at once will not be changed and returned. Thus, the outputs of the proposed D-PUF are not affected by the environment variable such as the operation voltage and temperature variation, etc. Consequently, the reliability of the proposed PUF will be enhanced owing to the proposed dual anti-fuse ROM. Therefore, the proposed D-PUF can be stably operated, in particular, without the powerful ECC in the external environment that are changed. 기존 SRAM 기반 PUF (physical unclonable function)는 난수 생성 및 키교환에 사용된다. SRAM에서 생성된 출력값은 일정하게 유지되어야 하나, 외부 환경에 의해 변화하는 문제가 발생된다. 본 논문은 듀얼 안티퓨즈 OTP (one time programmable) 메모리를 SRAM 기반 PUF에 채택한 새로운 구조의 D-PUF (deterministic PUF) 회로를 제안한다. 제안된 PUF 회로는 SRAM에서 한 번 생성된 출력값을 일정하게 계속 유지시켜 PUF 회로의 신뢰성을 향상시킬 수 있다. 우선, 높은 보안 수준을 갖는 안티퓨즈를 이용하여 OTP 메모리를 구성하였다. SRAM은 크로스 커플 인버터쌍의 미스매치를 이용하여 전원이 들어온 후 초기값을 임의로 생성하고 이를 출력한다. 마스킹된 출력값은 안티퓨즈 OTP ROM(read-only memory)에 난수값으로 프로그램된다. 한번 프로그램된 ROM 값은 되돌려지지도 변화하지도 않는다. 따라서, 제안된 D-PUF 회로는 SRAM의 출력값을 OTP 메모리에 저장시켜 한 번 결정된 PUF 출력값을 계속 유지시킨다. 제안된 D-PUF의 출력은 동작 전압 및 온도 변화 등과 같은 외부 환경 변수에 영향을 받지 않아 신뢰성이 향상된다. 따라서, 제안된 D-PUF는 강력한 오류 정정 코드없이 사용하더라도 안정적인 동작을 수행할 수 있다.

저비용 RFID 인증을 위한 PUF 기반 암호화 프로세서와 상호 인증 프로토콜 설계

최원석(Wonseok Che),김성수(Sungsoo Kim),김용환(Yonghwan Kim),윤태진(Taejin Yun),안광선(Kwangseon Ahn),한기준(Kijun Han) 한국통신학회 2014 韓國通信學會論文誌 Vol.39 No.12(네트워크)

RFID 시스템은 무선 통신을 이용하여 운용되기 때문에 외부의 불법적인 공격에 노출되어 있으며 이에 대한 시스템 침해의 위험성이 높다. 이러한 공격들에 대한 보안 기법들 중 PUF 기반의 인증 기법이 존재한다. 그러나 기존의 PUF 기반 기법들은 해쉬나 AES 알고리즘을 함께 이용하기 때문에, 비용 및 성능적인 측면에서 저비용 RFID 태그에 적합하지 않다. 본 논문에서는, 저비용 RFID 인증을 위하여 PUF 기반 암호화 프로세서와 이를 이용한 상호 인증 프로토콜을 제안한다. PUF의 challenge-response 쌍들을 인증키로 활용하고, 이를 PUF의 특성을 이용하여 암호화함으로써 해쉬 및 AES 등의 알고리즘 사용을 배제하였다. 매 세션마다 변경되는 암호화 방법과 일회성 난수를 이용한 XOR 연산 기법을 활용함으로써 공격자의 challenge-response 쌍에 대한 분석을 차단하여 시스템 공격을 무력화 시킨다. 또한, PUF 특성으로 인하여 물리적 공격에 강하고 태그에 저장된 인증 데이터가 존재하지 않기 때문에 물리적 공격에 의한 태그 복제 위험을 방지한다. 제안된 PUF 기반의 암호화 프로세서는 저비용으로 구현되며 저면적 및 저전력의 특징을 갖는다. The attacker can access the RFID systems illegally because authentication operation on the RFID systems are performed in wireless communication. Authentication methods based on the PUF were presented to defend attacks. Because of Hash and AES, the cost is expensive for the low-cost RFID tag. In this paper, the PUF-based encryption processor and the mutual authentication protocol are proposed for low-cost RFID authentication. The challenge-response pairs (PUF"s input and output) are utilized as the authentication key and encrypted by the PUF"s characteristics. The encryption method is changed each session and XOR operation with random number is utilized. Therefore, it is difficult for the attacker to analyze challenge-response pairs and attack the systems. In addition, the proposed method with PUF is strong against physical attacks. And the method protects the tag cloning attack by physical attacks because there is no authentication data in the tag. Proposed processor is implemented at low cost with small footprint and low power.

팽화처리가 홍미삼의 품질특성에 미치는 영향

한찬규(Chan-Kyu Han),홍희도(Hee-Do Hong),김영찬(Young-Chan Kim),김성수(Sung-Soo Kim),심건섭(Gun-Sub Sim) 고려인삼학회 2007 Journal of Ginseng Research Vol.31 No.3

팽화처리가 홍미삼의 사포닌 성분, 당류, 페놀성분, 미세구조 및 소화율 등에 미치는 영향을 조사하였다. 홍미삼의 추출된 조사포닌 함량은 팽화처리후 약 26.5% 증가하였다. 사포닌 조성에서 팽화홍미삼은 홍미삼에 비해 Rb₁, Rb₂, Rc, Re, Rg₁함량이 다소 감소하였으나 Rd와 Rg₃함량은 증가하였고, 특히 Rg₃함량은 0.49 ㎎/g에서 0.72 ㎎/g로 증가하였다. 가용성 총당은 팽화전후 비슷하였고, 산성다당체 함량은 각각 7.15, 6.44%로 팽화후 다소 감소하였다. 총페놀함량은 7.86%에서 9.94%로 증가하였다. 개별 페놀산의 경우 gentisic acid는 홍미삼에서만, salicylic acid는 팽화후 홍미삼에서만 검출되었고, gallic acid, p-coumaric acid, caffeic acid 및 ferulic acid 등은 팽화로 크게 감소한 반면 syringic acid는 약 6배 증가하였다. 팽화후 홍미삼의 절단면 미세구조는 팽화전보다 훨씬 균일화한 입자모양을 나타내었으며, 팽화전후 펩신소화율은 각각 22.4, 46.2%로 통계적으로 유의한 차이가 있었다 (p<0.05). 본 결과는 팽화처리에 의해 홍미삼의 생리활성성분의 증가와 기호성 및 소화율을 높일 수 있음을 시사하는 것으로 판단되었다. Effect of puffing treatment on saponins, total sugars, acidic polysaccharide, phenolic compounds, microstructure and pepsin digestibility of dried red ginseng tail root were tested. Puffing samples of dried red ginsneng tail root were prepared at 20rpm, 15 ㎏/㎠, 120~150℃, and for 30 min by a rotary type apparatus of 5 L capacity. Crude saponin content of puffing red ginseng tail root was increased 26.5% compared to non-puffing, especially Rg3 content was increased from 0.49 ㎎/g to 0.72 ㎎/g. Total sugar content was not changed, but acidic polysaccharide content was slightly decreased from 7.15% to 6.44% by puffing treatment. Total phenolic compounds was increased from 7.86% to 9.94% by puffing. In terms of individual phenolic compounds, salicylic acid was quantified in puffing tail root, but gentisic acid was quantified in non-puffing. Syringic acid was the most predominant phenolic acid, increased to about 6 times by puffing treatment. On the other hand, gallic acid, p-coumaric acid, caffeic acid and ferulic acid were highly decreased. Microstructure of crosssection in puffing tail root was shown to more uniform shape compared to non-puffing. Pepsin digestibilities of puffing and non puffing red ginseng tail root were 22.4% and 46.2%, respectively (p<0.05). The results indicated that puffing treatment might be useful increasing the bioactive components, preference and digestibility.

Effects of Organoclay on the Thermal Insulating Properties of Rigid Polyurethane Foams Blown by Environmentally Friendly Blowing Agents

Kim, Youn-Hee,Choi, Seok-Jin,Kim, Ji-Mun,Han, Mi-Sun,Kim, Woo-Nyon,Bang, Kyu-Tae The Polymer Society of Korea 2007 Macromolecular Research Vol.15 No.7

A process designed to synthesize rigid polyurethane foam (PUF) with insulative properties via the modulation of PUF cell size via the addition of clay and the application of ultrasound was assessed. The blowing agents utilized in this study include water, cyclopentane, and HFC-365mfc, all of which are known to be environmentally-friendly blowing agents. The rigid PUFs were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI) and polyether polyol with a density of $50kg/m^3$. In addition, rigid PUFs/clay nanocomposites were synthesized with clay modified by PMDI with and without the application of ultrasound. The PUF generated using water as a blowing agent evidenced the highest tensile strength. The tensile strength of the PUF/nanocomposites was higher than that of the neat PUF and the strength was even higher with the application of ultrasound. The cell size of the PUF/clay nanocomposites was less than that of the neat PUF, regardless of the type of blowing agent utilized. It appears that the higher tensile strength and lower cell size of the PUF/clay nanocomposites may be attributable to the uniform dispersion of the clay via ultrasonic agitation. The thermal conductivity of the PUF/clay nanocomposites generated with HCFC-141b evidenced the lowest value when PUF/clay nanocomposites were compared with other blowing agents, including HFC-365mfc, cyclopentane, and water. Ultrasound has also proven effective with regard to the reduction of the thermal conductivity of the PUF/clay nanocomposites with any of the blowing agents employed in this study. It has also been suggested that the uniformly dispersed clay particles in the PUF matrix function as diffusion barriers, which prevent the amelioration of the thermal insulation property.

비트연산자와 입력 위치 선택이 가능한 XAT(XOR-AND Transpose)-PUF에 관한 연구

백창재(Changjae Beak),박서현(Seo Hyeon Park),이정원(Jungwon Lee),선우경(Wookyung Sun) 대한전자공학회 2022 전자공학회논문지 Vol.59 No.12

MoS₂ 전 용액공정을 통한 Physically Unclonable Function 구현

김병민(Byenongmin Kim),김현성(Hyunsung Kim),박준영(Jun-Young Park) 대한전자공학회 2021 전자공학회논문지 Vol.58 No.10

Structural Design and Property Evaluations of Foam-based Composite Materials: Effect of Perforation Depth and Foam Density on the Mechanical, Sound Absorption, and Thermal Properties

Ruei-Ren Ou,Chen-Hung Huang,Ching-Wen Lou,Jia-Horng Lin 한국섬유공학회 2021 Fibers and polymers Vol.22 No.3

Nonwoven fabrics and rigid polyurethane foam(PUF) are commonly used materials as building materials, butthere are few studies on combining both materials and reporting characteristic evaluations for the application. In this study, N/L/Fr nonwoven fabrics are combined with PUF to produce N/PUF composites, and then a needle punching machine is usedfor perforation, thereby produces perforated N/PUF composites. With PUF densities being 70 kg/m3 and 80 kg/m3, aperforation depth of 100 % results in significantly decreasing mechanical properties. Based on the results of thermalconductivity coefficient, the employment of needle punch process results in a decrease in the thermal insulation of N/PUFcomposite; however, the descending level is comparatively smaller when PUF is made of a greater density. In thethermogravimetric analysis (TGA), the char residue is 4.86 % for PUF and 11.68 % for N/PUF composites, indicating thatN/L/Fr nonwoven fabrics improve the thermal stability of PUF. As per limiting oxygen index (LOI), the part of proposed N/PUF composites that first contacts the flame is N/L/Fr nonwoven fabrics, which causes an LOI of 33 when in practicalapplication and resembles the LOI (33) of N/L/Fr nonwoven fabrics. Based on the test results, the optimal perforated N/PUFcomposites are made of a PUF density of 80 kg/m3 and a perforation depth of 75 %, and the optimal compression strength is375.29 kPa, which increases by 10.96 %. In addition, the proposed products have the same impact absorption capacity (5.88 J) asthat of N/PUF composites, which absorb a total of 98.16 % impact energy. The sound absorption is improved in the frequencyband of 800-2500 Hz, which broadens the sound absorption bandwidth and benefits the application as being sound absorbentmaterials.

PUF 기반 RFID 인증 프로토콜의 효율적 설계에 관한 연구

변진욱(Jin Wook Byun) 한국정보보호학회 2014 정보보호학회논문지 Vol.24 No.5

PUF(physically unclonable function)는 태그 혹은 디바이스 내에 삽입되어 구현되며, 해당 디바이스의 고유한 물리적인 성질을 이용해서, 입력 값 x에 대해 노이지 y값을 출력한다. 비록 x가 동일하게 입력되더라도 매번 다른 출력 값(y₁,...yn)을 출력하며, 탬퍼 방지 (tamper-resistance) 성질로 인해, 암호 프로토콜에 활용도가 매우 높다. 본 논문에서는 이러한 PUF를 이용하여 RFID 인증 프로토콜을 안전하고 효율적으로 설계하는 방법에 대해 연구한다. 본 논문에서 제안된 방법은, 기존의 방법과 비교했을 시, 공격자가 메모리 노출 공격을 통해 비휘발성 메모리에 존재하는 롱텀(long-term) 키 값을 알게 되더라도, 그 세션 전후에 사용된 태그(tag)의 안전성 및 프라이버시가 보장되도록 설계하였다. 또한, PUF에 사용된 키 값을 복원하는 알고리즘이 태그 측이 아닌 RFID 리더에서 수행하도록 설계함으로써, 태그 구현 비용 및 전체 프로토콜 실행시간을 최소화할 수 있도록 하였다. A PUF is embedded and implemented into a tag or a device, and outputs a noise y with an input of x, based on its own unique physical characteristics. Although x is used multiple times as inputs of PUF, the PUF outputs slightly different noises, (y₁,...yn), and also the PUF has tamper-resistance property, hence it has been widely used in cryptographic protocol. In this paper, we study how to design a PUF-based RFID authentication protocol in a secure and an efficient way. Compared with recent schemes, the proposed scheme guarantees both authentication and privacy of backword/forward under the compromise of long-term secrets stored in tag. And also, the most cost and time-consumming procedure, key recovery algorithm used with PUF, has been desgined in the side of RFID reader, not in the tag, and, consequently, gives possibility to minimize costs for implementation and running time.

안전한 PUF 응답 전송을 위한 노이즈 삽입 및 복구 알고리즘 하드웨어 설계

강태근(Taegeun Kang),이현빈(Hyunbean Yi) 대한전자공학회 2017 전자공학회논문지 Vol.54 No.10

Shrink Generator-based Strong PUF Architecture with Improved Uniqueness and Reliability on an FPGA

Guard Kanda,Kwangki Ryoo 대한전자공학회 2023 Journal of semiconductor technology and science Vol.23 No.1

Silicon-based Physically Unclonable Functions (PUFs) are a source of physical security primitive that is either implemented on ASICs or FPGAs. A class of these security primitives that provide an exponentially large set of Challenge-Response Pairs (CRPs) is termed Strong PUF. That notwithstanding, the Arbiter and Feedforward Arbiter PUFs which are traditionally Strong PUFs, are not suitable for FPGA implementation. In this paper, a newly proposed PUF architecture that improves on the existing Configurable Ring Oscillator (CRO) PUF by increasing its dynamic configurability and its level of entropy is presented. To maintain the exponentially large set of CRPs, the Shrink Generator is applied to the traditionally Weak CRO-PUF. The proposed design is implemented and tested on a spartan-6 FPGA board using the Xilinx ISE tool. The proposed architecture demonstrates a uniqueness of 50.01% and is 96.43% reliable.