Crypto Library Research Articles

Analysis of Key Storage Mechanism of Asymmetric Key-Related Functions in CNG Crypto Library

During the implementation of a crypto system, distributed cryptographic libraries are unable to endure situations where the execution environment rapidly changes because of a structural vulnerability that is by design. For this reason, Microsoft announced a CNG library to solve this problem; however, the CNG does not comprise verification tools regarding the execution results for developers, users, or experts to assess the crypto system. In addition, the CNG design means that it is difficult to ensure that the encryption or decryption keys can be found in real-time processing because almost all cryptographic functions are processed by handles. This paper analyzes the way that key information is found to assure the security of the implemented products or to debug them in the development process. For this reason, we analyze the key storage mechanism of asymmetric-key-related functions in the CNG library. This study provides more convenient ways to identify key-related information, such as debugging and evaluation, when a crypto system is implemented using the CNG library.

ENCIDER: Detecting Timing and Cache Side Channels in SGX Enclaves and Cryptographic APIs

Confidential computing aims to secure the code and data in use by providing a Trusted Execution Environment (TEE) for applications using hardware features such as Intel SGX. Timing and cache side-channel attacks, however, are often outside the scope of the threat model, although once exploited they are able to break all the default security guarantees enforced by hardware. Unfortunately, tools detecting potential side-channel vulnerabilities within applications are limited and usually ignore the strong attack model and the unique programming model imposed by Intel SGX. This article proposes a precise side-channel analysis tool, ENCIDER, detecting both timing and cache side-channel vulnerabilities within SGX applications via inferring potential timing observation points and incorporating the SGX programming model into analysis. ENCIDER uses dynamic symbolic execution to decompose the side-channel requirement based on the bounded non-interference property and implements byte-level information flow tracking via API modeling. We have applied ENCIDER to 4 real-world SGX applications, 2 SGX crypto libraries, and 3 widely-used crypto libraries, and found 29 timing side channels and 73 code and data cache side channels. We also compare ENCIDER with three state-of-the-art side channel analysis tools using their benchmarks. ENCIDER does not only report most of the bugs with 20%-50% run time improvement and 65%-92% memory usage improvement, but also detects 9 missing bugs from these tools. We have reported our findings to the corresponding parties, e.g., Intel and ARM, who have confirmed most of the vulnerabilities detected.

Performance Analysis of SSL/TLS Crypto Libraries: Based on Operating Platform

. Security in Computer Network Communication is of great importance because unauthorized users attempt to steal, modify, misuse, interrupt, and try to un-stabilize, smartly our network systems. Therefore up to some extent, the secure communication provided by Transport Layer Protocol, implementation of the TLS function, and distinct libraries were designed by researchers, of which each library has the broad support of the encryption algorithms. But security can be compromised and seen in an offensive maneuver of the digital world as the main challenge in communication. In this paper, performance analysis of the most authentic six libraries: OpenSSL, AWS s2n, GnuTLS, NSS, BoringSSL, and Cryptlib performed to find appropriate TLS libraries for uncompromised communication based on throughput, CPU usage in the different virtual operating environments.

Runtime Randomized Relocation of Crypto Libraries for Mitigating Cache Attacks

Crypto libraries such as OpenSSL and Libgcrypt are essential building blocks for implementing secure cloud services. Unfortunately, these libraries are subject to cache side-channel attacks, which are more devastating in cloud environments where inevitable cache contention among different tenants occurs. Previous approaches for mitigating cache side-channel attacks have limitations in terms of the deployability and security; these hinder utilization in cloud services. In this paper, we propose an R2-relocator, a novel library protection technique based on moving target defence. When injected into a running process, the R2-relocator performs randomized relocation of the library during runtime. By doing this, it transforms a vulnerable crypto library into one that randomly changes its memory (cache) location, thereby preventing the delivery of cache side-channel attacks against the library. The proposed technique achieves robust protection against cache side-channel attacks for all crypto libraries, even those containing unpatched critical vulnerabilities, without the need for reconfiguration of the library. Extensive evaluations of security, performance, and deployability of the R2-relocator demonstrate its effectiveness for secure cloud services.

Efficient Implementation of a Crypto Library Using Web Assembly

We implement a cryptographic library using Web Assembly. Web Assembly is expected to show better performance than Javascript. The proposed library provides comprehensive algorithm sets including revised CHAM, Hash Message Authentication Code (HMAC), and ECDH using the NIST P-256 curve to provide confidentiality, data authentication, and key agreement functions. To optimize the performance of revised CHAM in the proposed library, we apply an existing method that is a four-round combining method and additionally propose the precomputation method to CHAM-64/128. The proposed revised CHAM showed an approximate 2.06 times (CHAM-64/128), approximate 2.13 times (CHAM-128/128), and approximate 2.63 times (CHAM-128/256) performance improvement in Web Assembly compared to JavaScript. In addition, CHAM-64/128 applying the precomputation method showed an improved performance by approximately 1.2 times more than the existing CHAM-64/128. For the ECDH using P-256 curve, the naive implementation of ECDH is vulnerable to side-channel attacks (SCA), e.g., simple power analysis (SPA), and timing analysis (TA). Thus, we apply an SPA and TA resistant scalar multiplication method, which is a core operation in ECDH. We present atomic block-based scalar multiplication by revising the previous work. Existing atomic blocks show a performance overhead of 55%, 23%, and 37%, but atomic blocks proposed to use only P=(X,Y,Z) show 18%, 6%, and 11% performance overhead. The proposed Web Assembly-based crypto library provides enhanced performance and resistance against SCA thus, it can be used in various web-based applications.

A novel accelerated implementation of RSA using parallel processing

Past research has evidently proved that public key cryptosystems are usually slower than symmetric key cryptosystems due to the reason that they use one additional cryptographic key and different methods for encryption and decryption. RSA is one of the most common asymmetric key cryptography algorithms. Recent research has focused on speeding up RSA using various techniques. With the introduction of distributed computing, parallelization of algorithms enables them to run on multiple cores concurrently at a time. RSA consists of two resource intensive operations namely Modular Exponentiation of up to 1024-bit exponents and repeated calculation of Greatest common divisor. Thus, RSA lays the perfect base for application of Montgomery Reduction algorithm to optimize the Repeated Modular multiplication in exponentiation. In this paper we proposed a parallel scheme for RSA using a new parallel data structure known as Concurrent Indexed List of character blocks. The aim of our research was to improve the speed of RSA encryption and decryption using parallelism and also make it compatible with leading industry cryptography standards. We have simulated four different approaches namely both parallel and sequential with and without Montgomery. We have also integrated our parallel paradigm with renowned C++ Crypto library and achieved a speed-up of upto four times than sequential approach. Unlike any other previous approaches, our implementation got easily integrated with any external library and thus can be adopted by any other algorithmic scheme.

안드로이드 플랫폼을 위한 자바 보안 프로바이더 설계 및 구현

안드로이드 기반 스마트기기에서 보안 응용 서비스를 개발하기 위해 SUN JCA/JCE나 BC JCE와 같은 자바 기반 보안 라이브러리를 사용한다. 자바를 사용하여 제작된 응용은 자바 가상 머신(JVM: Java Virtual Machine)에서 기능이 수행되므로 시스템 하드웨어에 의존하는 기능을 사용하기 어렵고 실행 속도가 저하되는 문제가 있다. 보안 프리미티브(primitive)의 경우 계산양이 많고 연산 복잡도가 높아 JVM에서 수행되는 보안 프리미티브를 적용할 수 있는 응용은 제한적이다. 특히, 실시간 특성을 요하는 스트리밍 서비스나 계산양이 많은 공개키 기반 알고리즘을 빈번히 적용하는 보안 응용 서비스의 경우 성능의 문제로 자바 라이브러리 사용이 어렵다. 이를 해결하기 위해 본 논문에서는 JNI와 NDK 도구를 사용하여 C나 C++ 언어로 구현된 네이티브 기능을 사용하여 보안 기능을 수행할 수 있는 프로바이더를 설계하고 구현한다. 제안하는 자바 보안 프로바이더(DSCrypt)는 기존 자바 기반 보안 라이브러리와 동일한 방식으로 사용할 수 있지만 빠르게 보안 기능이 수행되는 장점을 제공한다. Java crypto library such as SUN JCA/JCE or BC JCE is generally used to implement secure applications for smart devices using Android platform. Programming functions written by Java language are launched and executed inside Java Virtual Machine (JVM), thereby difficult to use system hardware specific functionalities and degrading performance as well. In case of crypto primitive, few secure applications can use crypto primitive executing in JVM because both amount of computing and complexity of such primitives are very high. From the aspect of performance, in particular, time sensitive real time applications such as streaming services or secure application frequently applying public key based crypto algorithm cannot use Java crypto library. To solve the problem, we design and implement crypto library which employ JNI and NDK methods to directly access functions that implemented by native language such as C or C++. The proposed Java Crypto provider supports faster execution. Also developer can use our provider in the same way by writing traditional Java crypto library.

Security Evaluation of GOST 28147-89 in View of International Standardisation

GOST 28147-89 is a well-known 256-bit block cipher that is a plausible alternative for AES-256 and triple DES, which, however, has a much lower implementation cost. GOST is implemented in standard crypto libraries, such as OpenSSL and Crypto++, and is increasingly popular and is used also outside of its country of origin and on the Internet. In 2010, GOST was submitted to ISO 18033 to become a worldwide industrial encryption standard. Until 2011, researchers unanimously agreed that GOST could or should be very secure, which was summarized at CHES 2010 conference in these words: “despite considerable cryptanalytic efforts spent in the past 20 years, GOST is still not broken.” Unhappily, it was recently discovered that GOST can be broken and is a deeply flawed cipher. One attack was already presented in February at FSE 2011. In this short paper, we describe another attack to illustrate the fact that there are now attacks on GOST, which require much less memory, and don't even require the so called ‘reflection property’ to hold, without which the recent attack from FSE 2011 wouldn't work. We are also aware of many substantially faster attacks and of some special, even weaker, cases. These will be published in appropriate peer-reviewed cryptography conferences but we must warn the ISO committees right now. More generally, our ambition is to do more than just point out that a major encryption standard is flawed. We would like to present and suggest a new general paradigm for effective symmetric cryptanalysis of so called “Algebraic Complexity Reduction.” We also explain the precise concept of “Black-box Algebraic Complexity Reduction.” This new paradigm builds on many already known attacks on symmetric ciphers, such as fixed point, slide, involution, cycling, and other self-similarity attacks, but the exact attacks we obtain could never be developed previously, because only in the most recent 5 years did it become possible to show the existence of an appropriate last step for many such attacks, which is a low data complexity software algebraic attack. This methodology leads to a large number of new attacks on GOST, cf. [12]. One example of such an attack is given in the present paper.