Universal Composability Notion for Functional Encryption Schemes

Sadikin, Rifki,Park, YoungHo,Park, KilHoum,Moon, SangJae Korea Society of Industrial Information Systems 2013 한국산업정보학회논문지 Vol.18 No.3

We have developed an ideal functionality for security requirement of functional encryption schemes. The functionality is needed when we want to show the security of a functional encryption scheme in universal composable (UC) framework. A functionality $F_{fe}$ was developed to represent ideal respond of a functional encryption scheme against any polynomial time active attacker. We show that UC security notion of functional encryption scheme $F_{fe}$ is as strong as fully secure functional encryption in an indistinguishable game with chosen cipher text attack. The proof used a method that showing for any environment algorithm, it can not distinguish ideal world where the attacker play with ideal functionality $F_{fe}$ and real world where the attacker play a fully secure functional encryption scheme.

Secure Attribute-Based Access Control with a Ciphertext-Policy Attribute-Based Encryption Scheme

Sadikin, Rifki,Park, Young Ho,Park, Kil Houm Korea Society of Industrial Information Systems 2014 한국산업정보학회논문지 Vol.19 No.1

An access control system is needed to ensure only authorized users can access a sensitive resource. We propose a secure access control based on a fully secure and fine grained ciphertext-policy attribute-based encryption scheme. The access control for a sensitive resource is ensured by encrypting it with encryption algorithm from the CP-ABE scheme parameterized by an access control policy. Furthermore, the proposed access control supports non-monotone type access control policy. The ciphertext only can be recovered by users whose attributes satisfy the access control policy. We also implement and measure the performance of our proposed access control. The results of experiments show that our proposed secure access control is feasible.

Ciphertext Policy-Attribute Based Encryption with Non Monotonic Access Structures

Rifki Sadikin(리프키 사디킨),SangJae Moon(문상재),YoungHo Park(박영호) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.9

CP-ABE 방식은 신뢰된 서버 없이 접근 제어 메카니즘을 구현할 수 있다. 본 논문에서는 권한을 부여받은 사용자가 민감한 데이터에 접근할 수 있도록 CP-ABE 방식으로 속성기반 접근 제어 메카니즘을 제안한다. CP-ABE 개념은 암호문에서 접근 제어 방법을 포함하는 것이다. 만약 사용자가 암호문의 접근 구조를 통해 속성을 가진다면 암호문은 복호될 수 있다. 본 논문에서는 제안한 CP-ABE 방식이 비단조 접근 구조로 표현됨을 증명하고 다른 CP-ABE 방식들과 성능 비교한다. A ciphertext policy-attribute based encryption(CP-ABE) scheme can be used to realize access control mechanism without a trusted server. We propose an attribute-based access control mechanism by incorporating a CP-ABE scheme to ensure only authorized users can access the sensitive data. The idea of CP-ABE is to include access control policy in the ciphertexts, in which they can only be decrypted if a user possesses attributes that pass through the ciphertext"s access structure. In this paper, we prove a secure CP-ABE scheme where the policy can be expressed in non-monotonic access structures. We further compare the performance of our scheme with the existing CP-ABE schemes.

Universal Composability Notion for Functional Encryption Schemes

Rifki Sadikin,YoungHo Park,KilHoum Park,SangJae Moon 한국산업정보학회 2013 한국산업정보학회논문지 Vol.18 No.3

We have developed an ideal functionality for security requirement of functional encryption schemes. The functionality is needed when we want to show the security of a functional encryption scheme in universal composable (UC) framework. A functionality Ffewas developed to represent ideal respond of a functional encryption scheme against any polynomial time active attacker. We show that UC security notion of functional encryption scheme Ffe is as strong as fully secure functional encryption in an indistinguishable game with chosen cipher text attack. The proof used a method that showing for any environment algorithm, it can not distinguish ideal world where the attacker play with ideal functionality Ffe and real world where the attacker play a fully secure functional encryption scheme.

Secure Attribute - Based Access Control with a Ciphertext-Policy Attribute - Based Encryption Scheme

Rifki Sadikin,Young Ho Park,Kil Houm Park 한국산업정보학회 2014 한국산업정보학회논문지 Vol.19 No.1

An access control system is needed to ensure only authorized users can access a sensitive resource. We propose a secure access control based on a fully secure and fine grained ciphertext-policy attribute-based encryption scheme. The access control for a sensitive resource is ensured by encrypting it with encryption algorithm from the CP-ABE scheme parameterized by an access control policy. Furthermore, the proposed access control supports non-monotone type access control policy. The ciphertext only can be recovered by users whose attributes satisfy the access control policy. We also implement and measure the performance of our proposed access control. The results of experiments show that our proposed secure access control is feasible.

Information Security on Learning Management System Platform from the Perspective of the User during the COVID-19 Pandemic

Mujiono Sadikin,Rakhmat Purnomo,Rafika Sari,Dyah Ayu Nabilla Ariswanto,Juanda Wijaya,Lydia Vintari 한국정보통신학회 2023 Journal of information and communication convergen Vol.21 No.1

Information security breach is a major risk in e-learning. This study presents the potential information security disruptions in Learning Management Systems (LMS) from the perspective of users. We use the Technology Acceptance Model approach as a user perception model of information security, and the results of a questionnaire comprising 44 questions for instructors and students across Indonesia to verify the model. The results of the data analysis and model testing reveals that lecturers and students perceive the level of information security in the LMS differently. In general, the information security aspects of LMSs affect the perceptions of trust of student users, whereas such a correlation is not found among lecturers. In addition, lecturers perceive information security aspect on Moodle is and Google Classroom differently. Based on this finding, we recommend that institutions make more intense efforts to increase awareness of information security and to run different information security programs.

Bilinear Group에서 속성 은닉을 가지는 안전한 내적 암호화 방식

리프키 사디킨(Rifki Sadikin),박영호(YoungHo Park) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.1

내적 암호화 방식은 비밀키와 암호문 사이에 파인 그레인 관계를 제공하는 암호학적 프리미티브이다. 본 논문은 완전한 속성 은닉 보호를 수행하는 새로운 IPE 방식을 제안한다. 제안한 IPE 방식은 합성 위수의 bilinear groups에 기반한다. 본 논문에서는 이중 암호화 시스템 체계를 사용하여 제안한 IPE의 완전한 속성 은닉 보호를 증명한다. 성능 분석에서 기존의 IPE 방식들과 제안한 IPE 방식의 연산량과 메모리 할당량을 비교한다. Inner product encryption (IPE) scheme is a cryptographic primitive that provides fine grained relations between secret keys and ciphertexts. This paper proposes a new IPE scheme which achieves fully attribute hiding security. Our IPE scheme is based on bilinear groups of a composite order. We prove the fully attribute hiding security of our IPE by using dual encryption system framework. In performance analysis, we compare the computation cost and memory requirement of our proposed IPE to other existing IPE schemes.

ISM Application Tool, A Contribution to Address the Barrier of Information Security Management System Implementation

Chandra, Nungky Awang,Sadikin, Mujiono The Korea Institute of Information and Commucation 2020 Journal of information and communication convergen Vol.18 No.1

Information-security management systems (ISMSs) are becoming very important, even for micro, small, and medium enterprises (MSMEs). However, implementing an ISMS is not an easy task. Many obstacles must be overcome, e.g., complexity, document tracking, competency management, and even changing cultures. The objective of our study is to provide ISMS application tools, based on ISO 27001:2013 ISM frameworks. The application was developed on the Odoo Open Enterprise Resource Planning platform. To validate its feasibility for future improvement, the application was implemented by an MSME company. For this implementation, information-security-related users gave their feedback through a questionnaire. The distributed feedback questionnaire consists of nine assessment parameters, covering topics from the application's technical aspects to users' experiences. Based on the questionnaire feedback, all users of the application were satisfied with its performance.

Closure of meningomyelocele defects using various types of keystone-design perforator island flaps

Putri, Nandita Melati,Tunjung, Narottama,Sadikin, Patricia Marcellina Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.3

Background Various methods have been described to close large meningomyelocele defects, but no technique has been proven superior to others. This study presents cases of meningomyelocele defect closure with a keystone-design perforator island flap. Methods A retrospective study was performed on 14 patients with meningomyelocele defects closed using various types of keystone flaps. Results The median age of the patients at surgery was 10.5 days (range, 1-369 days) and the average defect size was 22.5 cm² (range, 7.1-55.0 cm²). The average operative time for defect closure was 89.6 minutes (range, 45-120 minutes). Type IV bilateral keystone flaps were used for four defects, type IV unilateral flaps for six defects, type IIA flaps for two defects, and type III flaps for two defects. Conclusions All the defects healed completely with no major complications. The keystone-design perforator island flap is a reliable, easy, and fast technique to close large meningomyelocele defects.

Effects of α-tocopherol on hemolysis and oxidative stress markers on red blood cells in β-thalassemia major

Sovira, Nora,Lubis, Munar,Wahidiyat, Pustika Amalia,Suyatna, Franciscus D.,Gatot, Djajadiman,Bardosono, Saptawati,Sadikin, Mohammad The Korean Pediatric Society 2020 Clinical and Experimental Pediatrics (CEP) Vol.63 No.8

Background: The accumulation of unpaired α-globin chains in patients with β-thalassemia major may clinically create ineffective erythropoiesis, hemolysis, and chronic anemia. Multiple blood transfusions and iron overload cause cellular oxidative damage. However, α-tocopherol, an antioxidant, is a potent scavenger of lipid radicals in the membranes of red blood cells (RBCs) of patients with β-thalassemia major. Purpose: To evaluate the effects of α-tocopherol on hemolysis and oxidative stress markers on the RBC membranes of patients with β-thalassemia major. Methods: Forty subjects included in this randomized controlled trial were allocated to the placebo and α-tocopherol groups. Doses of α-tocopherol were based on Institute of Medicine recommendations: 4-8 years old, 200 mg/day; 9-13 years old, 400 mg/day; 14-18 years old, 600 mg/day. Hemolysis, oxidative stress, and antioxidant variables were evaluated before and after 4-week α-tocopherol or placebo treatment, performed before blood transfusions. Results: Significant enhancements in plasma haptoglobin were noted in the α-tocopherol group (3.01 mg/dL; range, 0.60-42.42 mg/dL; P=0.021). However, there was no significant intergroup difference in osmotic fragility test results; hemopexin, malondialdehyde, reduced glutathione (GSH), or oxidized glutathione (GSSG) levels; or GSH/GSSG ratio. Conclusion: Use of α-tocopherol could indirectly improve hemolysis and haptoglobin levels. However, it played no significant role in oxidative stress or as an endogen antioxidant marker in β-thalassemia major.