Cryptographic APIs Research Articles

Methods and Benchmark for Detecting Cryptographic API Misuses in Python

Methods and Benchmark for Detecting Cryptographic API Misuses in Python

Measurement of Embedding Choices on Cryptographic API Completion Tasks

In this article, we conduct a measurement study to comprehensively compare the accuracy impacts of multiple embedding options in cryptographic API completion tasks. Embedding is the process of automatically learning vector representations of program elements. Our measurement focuses on design choices of three important aspects, program analysis preprocessing , token-level embedding , and sequence-level embedding . Our findings show that program analysis is necessary even under advanced embedding. The results show 36.20% accuracy improvement, on average, when program analysis preprocessing is applied to transfer bytecode sequences into API dependence paths. With program analysis and the token-level embedding training, the embedding dep2vec improves the task accuracy from 55.80% to 92.04%. Moreover, only a slight accuracy advantage (0.55%, on average) is observed by training the expensive sequence-level embedding compared with the token-level embedding. Our experiments also suggest the differences made by the data. In the cross-app learning setup and a data scarcity scenario, sequence-level embedding is more necessary and results in a more obvious accuracy improvement (5.10%).

WEB CLOUD WEB-BASED CLOUD STORAGE FOR SECURE DATA SHARING ACROSS PLATFORMS

With more and more data moving to the cloud, privacy of user data have raised great concerns. Client-side encryption/decryption seems to be an attractive solution to protect data security, however, the existing solutions encountered three major challenges: low security due to encryption with low-entropy PIN, inconvenient data sharing with traditional encryption algorithms, and poor usability with dedicated software/plugins that require certain types of terminals. This work designs and implements WebCloud, a practical browser-side encryption solution, leveraging modern Web technologies. It solves all the above three problems while achieves several additional remarkable features: robust and immediate user revocation, fast data processing with offline encryption and outsourced decryption. Notably, our solution works on any device equipped with a Web user agent, including Web browsers, mobile and PC applications. We implement WebCloud based on ownCloud for basic file management utility, and utilize WebAssembly and Web Cryptography API for complex cryptographic operations integration. Finally, comprehensive experiments are conducted with many well-known browsers, Android and PC applications, which indicates that WebCloud is cross-platform and efficient. As an interesting by-product, the design of WebCloud naturally embodies a dedicated and practical ciphertext-policy attribute-based key encapsulation mechanism (CP-ABKEM) scheme, which can be useful in other applications.

Client-Side Encryption Based Secure Data Sharing Schemes for Cloud Platforms

Abstract: With more and more data moving to the cloud, privacy of user data have raised great concerns. Client-side encryption/decryption seems to be an attractive solution to protect data security, however, the existing solutions encountered three major challenges: low security due to encryption with low-entropy PIN, inconvenient data sharing with traditional encryption algorithms, and poor usability with dedicated software/plugins that require certain types of terminals. This work designs and implements Web Cloud, a practical browser-side encryption solution, leveraging modern Web technologies. It solves all the above three problems while achieves several additional remarkable features: robust and immediate user revocation, fast data processing with offline encryption and outsourced decryption. Notably, our solution works on any device equipped with a Web user agent, including Web browsers, mobile and PC applications. We implement Web Cloud based on own Cloud for basic file management utility, and utilize Web Assembly and Web Cryptography API for complex cryptographic operations integration. Finally, comprehensive experiments are conducted with many well-known browsers, Android and PC applications, which indicates that WebCloud is cross-platform and efficient. As an interesting by-product, the design of Web Cloud naturally embodies a dedicated and practical ciphertext- policy attribute-based key encapsulation mechanism (CP-AB-KEM) scheme, which can be useful in other applications

Analysis of pseudorandom number generation processes in EP CRYSTALS-Dilithium

The paper provides an analysis of pseudorandom number generation processes in the Crystals-Dilithium post-quantum electronic signature scheme, a finalist in the NIST PQC post-quantum cryptography competition. The main focus is on the pseudo-random number generator based on the AES block cipher in counter mode. A formal model was built for this pseudo-random number generator that meets the requirements of the latest version of the AIS 31 standard, containing requirements for secure pseudorandom number generators. A pseudo-random number generator based on the AES block cipher in counter mode is shown to satisfy the requirements of functional class DRG.3, provided that the initial value for the generator is obtained from a truly random number source (either a physically truly random or a non-physical truly random source) or another generator of pseudo-random numbers having a security class not lower than the DRG class.3. In addition, the use of shake128/256 for the generation of pseudorandom sequences in Crystals-Dilithium will be analyzed. Based on the results of the analysis, recommendations are given regarding the compilation parameters depending on the conditions of use. Namely, it is concluded that an AES-based generator is more vulnerable to side-channel attacks, from which it follows that it is not recommended to use the DILITHIUM_USE_AES flag unless there are additional guarantees to protect the machine from side-channel attacks. If the operating system's cryptographic API is trusted, it is recommended to use the DILITHIUM_RANDOMIZED_SIGNING compilation flag. In systems with low trust in the cryptographic API of the operating system, it is possible to use a variant with deterministic signature generation.

Intelligent Detection of Cryptographic Misuse in Android Applications Based on Program Slicing andTransformer-Based Classifier

The utilization of cryptography in applications has assumed paramount importance with the escalating security standards for Android applications. The adept utilization of cryptographic APIs can significantly enhance application security; however, in practice, software developers frequently misuse these APIs due to their inadequate grasp of cryptography. A study reveals that a staggering 88% of Android applications exhibit some form of cryptographic misuse. Although certain tools have been proposed to detect such misuse, most of them rely on manually devised rules which are susceptible to errors and require researchers possessing an exhaustive comprehension of cryptography. In this study, we propose a research methodology founded on a neural network model to pinpoint code related to cryptography by employing program slices as a dataset. We subsequently employ active learning, rooted in clustering, to select the portion of the data harboring security issues for annotation in accordance with the Android cryptography usage guidelines. Ultimately, we feed the dataset into a transformer and multilayer perceptron (MLP) to derive the classification outcome. Comparative experiments are also conducted to assess the model’s efficacy in comparison to other existing approaches. Furthermore, planned combination tests utilizing supplementary techniques aim to validate the model’s generalizability.

Temporal Data Correlation Providing Enhanced Dynamic Crypto-Ransomware Pre-Encryption Boundary Delineation.

Ransomware is a type of malware that employs encryption to target user files, rendering them inaccessible without a decryption key. To combat ransomware, researchers have developed early detection models that seek to identify threats before encryption takes place, often by monitoring the initial calls to cryptographic APIs. However, because encryption is a standard computational activity involved in processes, such as packing, unpacking, and polymorphism, the presence of cryptographic APIs does not necessarily indicate an imminent ransomware attack. Hence, relying solely on cryptographic APIs is insufficient for accurately determining a ransomware pre-encryption boundary. To this end, this paper is devoted to addressing this issue by proposing a Temporal Data Correlation method that associates cryptographic APIs with the I/O Request Packets (IRPs) based on the timestamp for pre-encryption boundary delineation. The process extracts the various features from the pre-encryption dataset for use in early detection model training. Several machine and deep learning classifiers are used to evaluate the accuracy of the proposed solution. Preliminary results show that this newly proposed approach can achieve higher detection accuracy compared to those reported elsewhere.

Industrial Experience of Finding Cryptographic Vulnerabilities in Large-scale Codebases

Enterprise environment often screens large-scale (millions of lines of code) codebases with static analysis tools to find bugs and vulnerabilities. Parfait is a static code analysis tool used in Oracle to find security vulnerabilities in industrial codebases. Recently, many studies show that there are complicated cryptographic vulnerabilities caused by misusing cryptographic APIs in Java TM 1 In this paper, we describe how we realize a precise and scalable detection of these complicated cryptographic vulnerabilities based on Parfait framework. The key challenge in the detection of cryptographic vulnerabilities is the high false alarm rate caused by pseudo-influences. Pseudo-influences happen if security-irrelevant constants are used in constructing security-critical values. Static analysis is usually unable to distinguish them from hard-coded constants that expose sensitive information. We tackle this problem by specializing the backward dataflow analysis used in Parfait with refinement insights, an idea from the tool CryptoGuard [ 20 ]. We evaluate our analyzer on a comprehensive Java cryptographic vulnerability benchmark and eleven large real-world applications. The results show that the Parfait-based cryptographic vulnerability detector can find real-world cryptographic vulnerabilities in large-scale codebases with high true-positive rates and low runtime cost.

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.

Evaluation of Static Vulnerability Detection Tools With Java Cryptographic API Benchmarks

Several studies showed that misuses of cryptographic APIs are common in real-world code (e.g., Apache projects and Android apps). There exist several open-sourced and commercial security tools that automatically screen Java programs to detect misuses. To compare their accuracy and security guarantees, we develop two comprehensive benchmarks named CryptoAPI-Bench and ApacheCryptoAPI-Bench. CryptoAPI-Bench consists of 181 unit test cases that cover basic cases, as well as complex cases, including interprocedural, field sensitive, multiple class test cases, and path sensitive data flow of misuse cases. The benchmark also includes correct cases for testing false-positive rates. The ApacheCryptoAPI-Bench consists of 121 cryptographic cases from 10 Apache projects. We evaluate four tools, namely, SpotBugs, CryptoGuard, CrySL, and another tool (anonymous) using both benchmarks. We present their performance and comparative analysis. The ApacheCryptoAPI-Bench also examines the scalability of the tools. Our benchmarks are useful for advancing state-of-the-art solutions in the space of misuse detection.

Automatic Detection of Java Cryptographic API Misuses: Are We There Yet?

The Java platform provides various cryptographic APIs to facilitate secure coding. However, correctly using these APIs is challenging for developers who lack cybersecurity training. Prior work shows that many developers misused APIs and consequently introduced vulnerabilities into their software. To eliminate such vulnerabilities, people created tools to detect and/or fix cryptographic API misuses. However, it is still unknown (1) how current tools are designed to detect cryptographic API misuses, (2) how effectively the tools work to locate API misuses, and (3) how developers perceive the usefulness of tools’ outputs. For this paper, we conducted an empirical study to investigate the research questions mentioned above. Specifically, we first conducted a literature survey on existing tools and compared their approach design from different angles. Then we applied six of the tools to three popularly used benchmarks to measure tools’ effectiveness of API-misuse detection. Next, we applied the tools to 200 Apache projects and sent 57 vulnerability reports to developers for their feedback. Our study revealed interesting phenomena. For instance, none of the six tools was found universally better than the others; however, CogniCrypt, CogniGuard, and Xanitizer outperformed SonarQube. More developers rejected tools’ reports than those who accepted reports (30 versus 9) due to their concerns on tools’ capabilities, the correctness of suggested fixes, and the exploitability of reported issues. This study reveals a significant gap between the state-of-the-art tools and developers’ expectations; it sheds light on future research in vulnerability detection.

CrySL: An Extensible Approach to Validating the Correct Usage of Cryptographic APIs

Various studies have empirically shown that the majority of Java and Android applications misuse cryptographic libraries, causing devastating breaches of data security. It is crucial to detect such misuses early in the development process. To detect cryptography misuses, one must <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">define</i> secure uses first, a process mastered primarily by cryptography experts but not by developers. In this paper, we present <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> , a specification language for bridging the cognitive gap between cryptography experts and developers. <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> enables cryptography experts to specify the secure usage of the cryptographic libraries they provide. We have implemented a compiler that translates such <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> specification into a context-sensitive and flow-sensitive demand-driven static analysis. The analysis then helps developers by automatically checking a given Java or Android app for compliance with the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> -encoded rules. We have designed an extensive <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> rule set for the Java Cryptography Architecture (JCA), and empirically evaluated it by analyzing 10,000 current Android apps and all 204,788 current Java software artefacts on Maven Central. Our results show that misuse of cryptographic APIs is still widespread, with 95 percent of apps and 63 percent of Maven artefacts containing at least one misuse. Our easily extensible <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CrySL</small> rule set covers more violations than previous special-purpose tools that contain hard-coded rules, while still offering a more precise analysis.

Digital Signature for data and documents using operating PKI certificates

This report represents my researching work for a six-month internship in Lex Persona Enterprise. "The implementation of applications that sign data and files electronically using operating digital certificates" is the central theme of this research. This project brings together many applications related to compliance with well-specified programming constraints to sign files electronically. The research has the goal of signing PDF documents digitally using the hash-and-sign method. The SHA-256 function as the hash function and RSA as encryption algorithm, accompanied with PKI certificates type X.509. The link between the applications and the certificates is the cryptographic API PKCS #11. This humbled work got dedicated to smartphones and computers. The use of WebView in all applications provides a taste of consistency. This article presents several processes carried out to accomplish this work.

WebCloud: Web-Based Cloud Storage for Secure Data Sharing Across Platforms

With more and more data moving to the cloud, privacy of user data have raised great concerns. Client-side encryption/decryption seems to be an attractive solution to protect data security, however, the existing solutions encountered three major challenges: low security due to encryption with low-entropy PIN, inconvenient data sharing with traditional encryption algorithms, and poor usability with dedicated software/plugins that require certain types of terminals. This work designs and implements WebCloud, a practical browser-side encryption solution, leveraging modern Web technologies. It solves all the above three problems while achieves several additional remarkable features: robust and immediate user revocation, fast data processing with offline encryption and outsourced decryption. Notably, our solution works on any device equipped with a Web user agent, including Web browsers, mobile and PC applications. We implement WebCloud based on ownCloud for basic file management utility, and utilize WebAssembly and Web Cryptography API for complex cryptographic operations integration. Finally, comprehensive experiments are conducted with many well-known browsers, Android and PC applications, which indicates that WebCloud is cross-platform and efficient. As an interesting by-product, the design of WebCloud naturally embodies a dedicated and practical ciphertext-policy attribute-based key encapsulation mechanism (CP-AB-KEM) scheme, which can be useful in other applications.

Client Module with Multifactor Authentication for Remote Electronic Signature Generation Using Cryptography API: Next Generation

In classic PKI systems, users resorted to cryptographic devices like smartcard or electronic-token to perform the required cryptographic operations, therefore all cryptographic operations will be done in a safe environment. Although a widely-accepted and highly-efficient method, along with the evolution of technology, it is also desirable to simplify user experience with the applications and at the same time to reduce costs. Thus, there is the problem of cryptographic devices and passwords needing to be retained and secret. To overcome all these impediments, we introduce the concept of remote signing, a concept that will simplify the signature generation process, and also increase security to the whole process while lowering costs for equipment. Therefore, by the fact that the signature generation process will be delegated to a remote service, the possibility of generating errors due to the client system is minimized, the need for a cryptographic device for users is eliminated. At the same time, the entire computational effort is also delegated to the remote service, which means an increased computing speed, and by the fact that the cryptographic devices that generate the signature are located at distance, there is also the possibility of physical securing and limiting unauthorized access.

Vulvet

Data security and privacy of Android users is one of the challenging security problems addressed by the security research community. A major source of the security vulnerabilities in Android apps is attributed to bugs within source code, insecure APIs, and unvalidated code before performing sensitive operations. Specifically, the major class of app vulnerabilities is related to the categories such as inter-component communication (ICC), networking, web, cryptographic APIs, storage, and runtime-permission validation. A major portion of current contributions focus on identifying a smaller subset of vulnerabilities. In addition, these methods do not discuss how to remove detected vulnerabilities from the affected code. In this work, we propose a novel vulnerability detection and patching framework, Vulvet , which employs static analysis approaches from different domains of program analysis for detection of a wide range of vulnerabilities in Android apps. We propose an additional light-weight technique, FP-Validation, to mitigate false positives in comparison to existing solutions owing to over-approximation. In addition to improved detection, Vulvet provides an automated patching of apps with safe code for each of the identified vulnerability using bytecode instrumentation. We implement Vulvet as an extension of Soot. To demonstrate the efficiency of our proposed framework, we analyzed 3,700 apps collected from various stores and benchmarks consisting of various weak implementations. Our results indicate that Vulvet is able to achieve vulnerability detection with 95.23% precision and 0.975 F-measure on benchmark apps; a significant improvement in comparison to recent works along with successful patching of identified vulnerabilities.

Scrutinizing and Appraising the Usages of Cryptographic API

Developing and maintaining an appropriate series of safety regulations that balance the abuse of cryptographic APIs is a daunting task as cryptographic APIs are continually changing with new primeval and cryptographic settings, rendering current versions balanced. We are proposing a new approach to eliminating security patches from thousands of code changes in order to resolve this challenge. Our approach involves (i) detecting program modifications that sometimes cause security fixes, (ii) an abstraction that filters trivial code changes (such as refactoring), and (iii) a cluster analysis that recognizes similarities between semantine program modifications and helps to obtain safety laws. We used our approach to the Java Crypto API and demonstrated that it is effective: (i) effectively filter changes in non-modification code (more than 99% of all changes) without removing them from our abstraction, and (ii) over 80 percent of code changes are security fixes that define security rules. We have established 13 rules, including new ones, based on our findings, that are not supported by existing security checks. CCS COCEPTS: Security and privacy → Systems security; Cryptanalysis and other attacks; Software security engineering;

Crypto Ransomware Detection on Windows Operating System

Crypto-ransomware is a kind of malware threat, and it is one of approach frequently used by cybercriminals. It is due to the capability to hijack the victim’s files and data by totally encrypting it using sophisticated cryptographic libraries such as OpenSSL and Microsoft Cryptography API. From the ransom note left by the attacker on the infected machine, the victim is told to fulfil the requested payment to get back the files. New variants of ransomware were released from time to time, thus making the task of detecting and analyzing it becomes challenging and resource consuming. Obfuscation and polymorphism employed in most modern malware made the task of identifying it even harder. This research investigates the domain of detecting ransomware on a Windows-based platform. We reviewed some of the related works done within this domain. In this research work, we proposed a framework for crypto-ransomware detection on the Windows-based platform by using information such as API calls and registry.

Захист віртуальних машин на основі інструкцій нового покоління процесорів AMD Zen

It is demonstrated the development of a virtualization environment security subsystem with the help of hardware-accelerated AMD Zen CPU cryptography API and its instruction set for security tasks, including but not limited to: protection against unauthorized memory access, data leaks, hypervisor breach, external attacks and malware spread via the Internet. The method in question utilizes real-time memory encryption and decryption, with the memory bandwidth and computing power sufficient for seamless hypervisor and server operation, virtual machine live migration and secure export, and demonstrates capabilities of ARM Cortex A5 on-board cryptography processor core for mentioned tasks, as well as providing secure asymmetric key exchange invisible and inaccessible to any software beside internal Trusted Platform Module and its inner DRAM memory controller, to guarantee high level of virtual environment security and sufficient resistance to most active attacks with minimum computation overhead, suitable for most real-life virtualization-based workload scenarios. The example subsystem specifically targets Microsoft Windows 10 operating system, however software support for different operating systems (including UNIX-based) may already be provided by appropriate vendors, including enterprise-ready solutions, such as Cisco, Dell, HP, etc.

Developers are Not the Enemy!: The Need for Usable Security APIs

Rather than recognizing software engineers' limitations, modern security practice has created an adversarial relationship between security software designers and the developers who use their software to construct applications. Using the example of cryptographic APIs, the authors show that developers aren't the enemy and that, to strengthen security systems across the board, security professionals must focus on creating developer-friendly and developer-centric approaches.