In-memory dynamic graph processing faces three critical challenges: limited DRAM capacity, inefficient concurrent update/query handling, and vulnerability to crashes. Traditional segment-level systems struggle with write amplification on emerging Storage-Class Memory (SCM), while existing persistent-memory systems suffer from coarse-grained synchronization and high recovery overhead. This study presents the Storage-Class Memory Dynamic Graph (SMDG) processing framework, an architecture-level redesign centered on the block as the atomic unit across storage, concurrency, and recovery. The system addresses these challenges through three key innovations. First, a block-granular storage design organizes adjacency data at fixed-size block granularity on heterogeneous DRAM-SCM architecture, employing buffered batched writes to significantly reduce write amplification while preserving logarithmic update complexity. Second, block-level multi-version concurrency control maintains timestamped block versions under per-vertex read-write synchronization to provide task-ordered snapshot visibility for concurrent queries without copying entire vertices or pages. Third, a block-granular crash recovery protocol with decentralized per-vertex logs enables independent parallel reconstruction, ensuring application-level semantic consistency while achieving substantially faster recovery than sequential approaches. Experimental results validate that this unified block-granular design improves update efficiency, sustains mixed update-query workloads with controlled memory overhead, and accelerates crash recovery compared with prior dynamic graph systems.

This paper addresses the pressing need for effective k-tips decomposition in dynamic bipartite graphs, a crucial aspect of real-time applications that analyze and mine binary relationship patterns. Recognizing the dynamic nature of these graphs, our study is the first to provide a solution for k-tips decomposition in such evolving environments. We introduce a pioneering projection-based algorithm, coupled with advanced incremental maintenance strategies for edge modifications, tailored specifically for dynamic graphs. This novel approach not only fills a significant gap in the analysis of dynamic bipartite graphs but also substantially enhances the accuracy and timeliness of data-driven decisions in critical areas like public health. Our contributions set a new benchmark in the field, paving the way for more nuanced and responsive analyses in various domains reliant on dynamic data interpretation.

With increasing demands for privacy, it becomes necessary to protect sensitive user query data when accessing public key-value databases. Existing Private Information Retrieval (PIR) schemes provide full security but suffer from poor scalability, limiting their applicability in large-scale deployment. We argue that in many real-world scenarios, a more practical solution should allow users to flexibly determine the privacy levels of their queries in a theoretically guided way, balancing security and performance based on specific needs. To formally provide provable guarantees, we introduce a novel concept of distance-based indistinguishability, which can facilitate users to comfortably relax their security requirements. We then design Femur, an efficient framework to securely query public key-value stores with flexible security and performance trade-offs. It uses a space-efficient learned index to convert query keys into storage locations, obfuscates these locations with extra noise provably derived by the distance-based indistinguishability theory, and sends the expanded range to the server. The server then adaptively utilizes the best scheme to retrieve data. We also propose a novel variable-range PIR scheme optimized for bandwidth-constrained environments. Experiments show that Femur outperforms the state-of-the-art designs even when ensuring the same full security level. When users are willing to relax their privacy requirements, Femur can further improve the performance gains to up to 163.9X, demonstrating an effective trade-off between security and performance.

This paper addresses the pressing need for effective k-tips decomposition in dynamic bipartite graphs, a crucial aspect of real-time applications that analyze and mine binary relationship patterns. Recognizing the dynamic nature of these graphs, our study is the first to provide a solution for k-tips decomposition in such evolving environments. We introduce a pioneering projection-based algorithm, coupled with advanced incremental maintenance strategies for edge modifications, tailored specifically for dynamic graphs. This novel approach not only fills a significant gap in the analysis of dynamic bipartite graphs but also substantially enhances the accuracy and timeliness of data-driven decisions in critical areas like public health. Our contributions set a new benchmark in the field, paving the way for more nuanced and responsive analyses in various domains reliant on dynamic data interpretation.

In contemporary database applications, the demand for memory resources is intensively high. To enhance adaptability to varying resource needs and improve cost efficiency, the integration of diverse storage technologies within heterogeneous memory architectures emerges as a promising solution. Despite the potential advantages, there exists a significant gap in research related to the security of data within these complex systems. This paper endeavors to fill this void by exploring the intricacies and challenges of ensuring data security in object-oriented heterogeneous memory systems. We introduce the concept of Unified Encrypted Memory (UEM) management, a novel approach that provides unified object references essential for data management platforms, while simultaneously concealing the complexities of physical scheduling from developers. At the heart of UEM lies the seamless and efficient integration of data encryption techniques, which are designed to ensure data integrity and guarantee the freshness of data upon access. Our research meticulously examines the security deficiencies present in existing heterogeneous memory system designs. By advancing centralized security enforcement strategies, we aim to achieve efficient object-centric data protection. Through extensive evaluations conducted across a variety of memory configurations and tasks, our findings highlight the effectiveness of UEM. The security features of UEM introduce low and acceptable overheads, and UEM outperforms conventional security measures in terms of speed and space efficiency.

In response to escalating concerns about data privacy in the Large Language Model (LLM) domain, we demonstrate EncChain , a pioneering solution designed to bolster data security in LLM applications. EncChain presents an all-encompassing approach to data protection, encrypting both the knowledge bases and user interactions. It empowers confidential computing and implements stringent access controls, offering a significant leap in securing LLM usage. Designed as an accessible Python package, EncChain ensures straightforward integration into existing systems, bolstered by its operation within secure environments and the utilization of remote attestation technologies to verify its security measures. The effectiveness of EncChain in fortifying data privacy and security in LLM technologies underscores its importance, positioning it as a critical advancement for the secure and private utilization of LLMs.

The increasing prevalence of data breaches necessitates robust data protection measures in computational tasks. Secure computation outsourcing (SCO) presents a viable solution by safeguarding the confidentiality of inputs and outputs in data processing without disclosure. Nonetheless, this approach assumes the existence of a trustworthy coordinator to orchestrate and oversee the process, typically implying that data owners must fulfill this role themselves. In this paper, we consider secure delegated data processing (SDDP), an expanded data processing scenario wherein data owners simply delegate their data to SDDP providers for subsequent value mining or other downstream applications, eliminating the necessary involvement of data owners or trusted entities to dive into data processing deeply. However, general-purpose SDDP poses significant challenges in permitting the discretionary execution of computational tasks by SDDP providers on sensitive data while ensuring confidentiality. Existing approaches are insufficient to support SDDP in either efficiency or universality. To tackle this issue, we propose TGCB, a TEE-based General-purpose Computational Backend, designed to endow general-purpose computation with SDDP capabilities from an engineering perspective, powered by TEE-based code integrity and data confidentiality. Central to TGCB is the Encryption Programming Language (EPL) that defines computational tasks in SDDP. Specifically, SDDP providers can express arbitrary computable functions as EPL scripts, processed by TGCB's interfaces, securely interpreted and executed in TEE, ensuring data confidentiality throughout the process. As a universal computational backend, TGCB extensively bolsters data security in existing general-purpose computational tasks, allowing data owners to leverage SDDP without privacy concerns.

GPU's massive computing power offers unprecedented opportunities to enable large graph analysis. Existing studies proposed various preprocessing approaches that convert the input graphs into dedicated structures for GPU-based optimizations. However, these dedicated approaches incur significant preprocessing costs as well as weak programmability to build general graph applications. In this paper, we introduce SAGE, a self-adaptive graph traversal on GPUs, which is free from preprocessing and operates on ubiquitous graph representations directly. We propose Tiled Partitioning and Resident Tile Stealing to fully exploit the computing power of GPUs in a runtime and self-adaptive manner. We also propose Sampling-based Reordering to further optimize the memory efficiency of SAGE through a lightweight and effective node reordering technique on the fly. Extensive experiments demonstrate that SAGE can achieve superior graph traversal performance over existing approaches under different architectural scenarios, i.e., single-GPU, out-of-core, and multi-GPU.

Cache efficiency is an important factor in the performance of graph processing due to the irregular memory access patterns caused by the sparse nature of graphs. To increase the cache hit rate, prior studies proposed a variety of preprocessing approaches based on the reordering, which permutes the vertexes’ labels to improve the locality of graph structures. However, the locality enhancement of existing reordering approaches does not bring much performance benefit in depth-first traversal, which is widely adopted in a majority of graph processing applications. Furthermore, the state-of-the-art reordering approach suffers from an obvious overhead on preprocessing which will greatly limit the application of their approach. In this paper, we propose SeqDFS, a depth-first graph traversal method that optimizes the cache efficiency by adjusting the order of vertexes visited and can be further extended to dynamic scenarios. We conduct extensive experiments on 16 real-world datasets and 3 representative depth-first graph applications, of which the results show that our proposal achieves a significant speed-up on both directed and undirected graphs.

Subgraph enumeration is important for many applications such as network motif discovery and community detection. Recent works utilize graphics processing units (GPUs) to parallelize subgraph enumeration, but they can only handle graphs that fit into the GPU memory. In this paper, we propose a new approach for GPU-accelerated subgraph enumeration that can efficiently scale to large graphs beyond the GPU memory. Our approach divides the graph into partitions, each of which fits into the GPU memory. The GPU processes one partition at a time and searches the matched subgraphs of a given pattern (i.e., instances) within the partition as in the small graph. The key challenge is on enumerating the instances across different partitions, because this search would enumerate considerably redundant subgraphs and cause the expensive data transfer cost via the PCI-e bus. Therefore, we propose a novel shared execution approach to eliminate the redundant subgraph searches and correctly generate all the instances across different partitions. The experimental evaluation shows that our approach can scale to large graphs and achieve significantly better performance than the existing single-machine solutions.

Graph processing on GPUs received much attention in the industry and the academia recently, as the hardware accelerator offers attractive potential for performance boost. However, the high-bandwidth device memory on GPUs has limited capacity that constrains the size of the graph to be loaded on chip. In this paper, we introduce GPU-based graph traversal on compressed graphs, so as to enable the processing of graphs having a larger size than the device memory. Designed towards GPU's SIMT architecture, we propose two novel parallel scheduling strategies Two-Phase Traversal and Task-Stealing to handle thread divergence and workload imbalance issues when decoding the compressed graph. We further optimize our solution against power-law graphs by proposing Warp-centric Decoding and Residual Segmentation to facilitate parallelism on processing skewed out-degree distribution. Extensive experiments show that with 2x-18x compression rate, our proposed GPU-based graph traversal on compressed graphs (GCGT) achieves competitive efficiency compared with the state-of-the-art graph traversal approaches on non-compressed graphs.

We study the important problem of user alignment in e-commerce: to predict whether two online user identities that access an e-commerce site from different devices belong to one real-world person. As input, we have a set of user activity logs from Taobao and some labeled user identity linkages. User activity logs can be modeled using a heterogeneous interaction graph (HIG), and subsequently the user alignment task can be formulated as a semi-supervised HIG embedding problem. HIG embedding is challenging for two reasons: its heterogeneous nature and the presence of edge features. To address the challenges, we propose a novel Heterogeneous Embedding Propagation (HEP) model. The core idea is to iteratively reconstruct a node's embedding from its heterogeneous neighbors in a weighted manner, and meanwhile propagate its embedding updates from reconstruction loss and/or classification loss to its neighbors. We conduct extensive experiments on large-scale datasets from Taobao, demonstrating that HEP significantly outperforms state-of-the-art baselines often by more than 10% in F-scores.

Personalized PageRank (PPR) is a well-known proximity measure in graphs. To meet the need for dynamic PPR maintenance, recent works have proposed a local update scheme to support incremental computation. Nevertheless, sequential execution of the scheme is still too slow for highspeed stream processing. Therefore, we are motivated to design a parallel approach for dynamic PPR computation. First, as updates always come in batches, we devise a batch processing method to reduce synchronization cost among every single update and enable more parallelism for iterative parallel execution. Our theoretical analysis shows that the parallel approach has the same asymptotic complexity as the sequential approach. Second, we devise novel optimization techniques to effectively reduce runtime overheads for parallel processes. Experimental evaluation shows that our parallel algorithm can achieve orders of magnitude speedups on GPUs and multi-core CPUs compared with the state-of-the-art sequential algorithm.

As graph analytics often involves compute-intensive operations, GPUs have been extensively used to accelerate the processing. However, in many applications such as social networks, cyber security, and fraud detection, their representative graphs evolve frequently and one has to perform a rebuild of the graph structure on GPUs to incorporate the updates. Hence, rebuilding the graphs becomes the bottleneck of processing high-speed graph streams. In this paper, we propose a GPU-based dynamic graph storage scheme to support existing graph algorithms easily. Furthermore, we propose parallel update algorithms to support efficient stream updates so that the maintained graph is immediately available for high-speed analytic processing on GPUs. Our extensive experiments with three streaming applications on large-scale real and synthetic datasets demonstrate the superior performance of our proposed approach.