AUTHORSHIP INTEGRITY. For both Paillier and ElGamal, we define decryption that can handle negative numbers as: We use post-encryption packing to pack these four values into a single ciphertext, thereby reducing the ciphertext size by 4. Computing on encrypted data introduces the additional challenge of dealing with operands with increased sizes. All authors must be explicitly identified at the time of submission. We contrast C3PO with related work in Section 10 and conclude with final remarks in Section 11. (14) \[\begin{equation} K_{c,f,g} = \textrm {PRP}_{\textrm {MK}}(c, f, g), \end{equation}\] where PRP is a pseudo-random permutation (e.g., AES block cipher) and MK is the master key, known only to the key manager, from which all other keys are derived. The Editor-in-Chief forwards the paper to an Editor for processing. Deserialize the JSON formatted event string into individual event fields. Public clouds are also preferred because of the variety of software services they provide that make the development and deployment of corresponding applications very fast. MHE schemes include the ElGamal [18] and unpadded RSA [50] cryptosystems. The same rules apply to Special Issue papers. Cuttlefish [53] is another recent system that uses PHE. A promising approach to overcome this bottleneck is to use homomorphic encryption and execute all operations over encrypted data. CryptDB [48] is a database system focusing on executing SQL queries on encrypted data using PHE. 2:1-2:31. Copyright 2023 ACM, Inc. http://www.acm.org/publications/authors/submissions, ACM Policy on Prior Publication and Simultaneous Submissions, Publications Policy on Research Involving Human Participants and Subjects, Policy on Roles and Responsibilities in ACM Publishing page, HOW TO CLASSIFY WORKS USING ACM'S COMPUTING CLASSIFICATION SYSTEM, ACM Transactions on Architecture and Code Optimization, ACM Transactions on Human-Robot Interaction, ACM Transactions on Programming Languages and Systems, ACM Transactions on Probabilistic Machine Learning, Proceedings of the ACM on Programming Languages, https://www.acm.org/publications/authors/submissions, https://www.overleaf.com/gallery/tagged/acm-official#.WOuOk2e1taQ, All Holdings within the ACM Digital Library. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Performance evaluation (Section 9): We evaluate C3PO on multiple benchmarks and case studies. For Q1, Q2, Q3, and Q5, we are able to mask one field, resulting in an average of 7% increase in throughput. In other words, addition and deletion of authors is not allowed, unless permission is granted by the Editor-in-Chief. The Editor-in-Chief or his delegate may optionally make a quick assessment on suitability and viability of the paper for TOPS. STYX promoted similar programming abstractions as C3PO but did not allow for limited key sharing in time (key rotations) or space (multiple groups). 11. The deployment steps are detailed in Section 7. C is derived by inverting the number of instances for each vertex (from the deployment profile) in the plaintext version of the graph and then scaling it with respect to the crypto operations performed by the vertex. Although there is nothing really "typical" about such things, a turn around time of 3-4 months for the first round of reviews is a reasonable expectation. Next, we study how C3PO can be used for an online healthcare application like a heartbeat monitor. Multi-group mode allows us to rotate the key of a specific group, reducing the impact of key rotations. Your file of search results citations is now ready. Finally, processing continuous queries typically involves a pipeline of computing tasks, each of which may have one or more instances running concurrently. Post-encryption packing. The number of items that the map can hold is configurable and adjusted depending on the memory capacity of each IoT device. Theoretical papers must provide compelling examples and make convincing arguments for the practical significance of their results. We propose a linear programming-based heuristic that automatically converts the deployment profile for a plaintext graph into an optimized deployment profile for the corresponding C3PO graph. However, there is great reluctance to share if data sovereignty is not provided. We can see that C3PO with no key changes completes processing the data with only a 23.8% and 25.1% increase of completion time and average response time, respectively, compared to the Storm running on a plaintext stream. Adoption of PHE and even FHE for generic application development will depend on the ease with which a programmer can incorporate the properties offered by the cryptosystem into their regular programming tasks. Multiplication between a packed ciphertext and a packed plaintext is not supported but multiplication between a packed ciphertext and a single (unpacked) plaintext value is supported using Equation (4), since mathematically \((a_1 \circ \cdots \circ a_n) \times b = (a_1 \times b) \circ \cdots \circ (a_n \times b)\). Fig. This step identifies the cryptosystems that are required for the various fields based on the operations that the application wishes to perform on those fields. (4) \[\begin{equation} D(E(x_1)^{x_2} \bmod N^2) = (x_1 \times x_2) \bmod N \end{equation}\] It is published by Association for Computing Machinery (ACM). Figure 4 illustrates this. ARM Cortex-M3 with a 72 MHz 32-bit microprocessor and 64 KB RAM. Execution proceeds only if the hash is verified. Alternatively, C3PO can be configured to perform all divisions in the trusted tier that poses no restrictions on the division operands. (5) \[\begin{equation} D(E(x_1) \times E(x_2)^{-1} \bmod N^2) = (x_1 - x_2) \bmod N \end{equation}\] Similarly, the ElGamal cryptosystem [18] supports multiplication and division (multiplication with the multiplicative inverse) between two encrypted values and multiplication/exponentiation between an encrypted and a plaintext value. View Figure These instructions are limited to LaTex and MSWord. Seabed [45] introduces an additively symmetric homomorphic encryption scheme to perform aggregations on large encrypted datasets efficiently. C3PO also supports packing for MHE, but to a limited degree, because in multiplication each packed item of a ciphertext is multiplied with all packed items of the other ciphertext. The results of our evaluation are presented in Figure 10. In this plot, we can see intermittent spikes (total of 12) in response time for some tuples around the time a key change is in progress, but the majority of tuples (90th percentile within 31 ms and 99th percentile within 818 ms) respond with the same response time as when no change was in effect. This means that all data is emitted with a timestamp within the first 30 minutes of every month will be encrypted under both the old and new keys. Private Inference is the task of evaluating NN without leaking private inputs. ACM style files will closely approximate the final output, enabling authors to judge the page-length of their published articles. Many IoT applications, therefore, leverage the cloud to compute on data streams from a large number of devices. Heartbeat analysis: We use a heartbeat analysis application that computes individual and group statistics. At the processing end, multiple groups lead to additional tasks for C3POVertex. To be practical, network updates must be consistent (i.e., free of transient errors caused by updates to multiple We propose to identify compromised mobile devices from a network administrators point of view. [19] to pack multiple plaintext values into a single ciphertext. The bandwidth of the trusted node was throttled to 8 Mbit/s to simulate a wide area network link. Correspondence with the authors regarding revisions is typically done by the Editor. know that Paillier is the correct cryptosystem to use for performing additions; explicitly read the Paillier public key (Line 3) that contains the generator, \(g\), and the modulus, \(N\); and. We also plot response times for all notification triggering tuplestimes taken for notifications to be issued from the time respective tuples enter the system. Common grouping clauses are: shuffle grouping tuples are distributed randomly across tasks in such a way that each task gets an equal number of tuples, field grouping tuples are partitioned according to a designated field and distributed among tasks, and. 9. C3PO cannot identify what homomorphic division operations will fail a priori, but it can detect what division operations have failed after the results have been decrypted. Editing is available for both Word and LaTeX files. Once all values per key are combined the emit() function emits each key-value pair as a separate tuple. We use cookies to ensure that we give you the best experience on our website. In this section, we present background information on PHE, PPE, and the cryptosystems employed by C3PO. Fig. But with this surge in popularity comes increased risk to privacy as the technology makes it easy to spy on people in otherwise-private environments, such as an individuals We use cookies to ensure that we give you the best experience on our website. Secondary homomorphic operations are supported after packing but with some alterations. After the re-encryption step, the query can correctly handle tuples encrypted with new keys. Fig. To make PHE and PPE schemes more suitable for IoT devices, we present extensions and optimizations applied to them in Section 5, where we also discuss how C3PO handles overflows while supporting negative numbers. C3PO operates on streaming data without revealing any plaintext information to the untrusted cloud. Automatic re-encryption (4). The malware analysis and detection research community relies on the online platform VirusTotal to label Android apps based on the scan results of around 60 antiviral scanners. Havet et al. If there is a continuous query that finds unique groups, then the second field will be unused. In this section, we introduce a set of optimizations as well as extensions to previously proposed optimizations to reduce time and space overheads associated with PHE and PPE encryption, making these schemes more practical for use in resource-constrained devices, thereby addressing challenge 5. Since an unused field may be at any index within a tuple, if we simply drop the field, then program logic that accesses other fields using their indices may fail. The ACM Digital Library is published by the Association for Computing Machinery. C3PO leverages this fact to improve the performance of encryption. We also consider IoT device compromises out of the scope of our article and focus on preserving the confidentiality of data in the untrusted cloud. To perform equality comparisons, these values need to be encrypted under a deterministic scheme. Each vertex of the graph may have multiple runtime instantiations called tasks. List. 2. The system runs at a throughput of 1,763 tuples per second when no keys are changed. perform the exact computation \(\psi\) (see Equation (1)) for homomorphic addition with Pailliermultiplication modulo the square of the modulus \(N\) of the public key (Line 11)including handling of null values (Line 10). Fig. Source vertices act as entry points for data into the graph. After presenting background information on PHE, PPE, and continuous queries (Section 2) and giving an overview of our solution (Section 3) including the assumed threat model and architecture of C3PO, this article makes the following contributions through C3PO and its features as outlined below: Programming abstractions (Section 4): We propose an abstraction of secure streams, embodied in the C3PO API for typical plaintext streams, to enable programmers to conveniently express confidentiality-preserving continuous query programs. y-axis in log scale. (This license is roughly the equivalent of ACMs traditional Copyright Transfer Agreement except that the author continues to hold copyright. These concerns represent a significant deterrent for industry domains like healthcare to adopt public clouds. To apply these inferences, C3PO first has to identify different streams and their grouping clauses in the application logic. Secure Systems: secure operating systems, database systems and networks; secure distributed systems including security middleware; secure web browsers, servers, and mobile code; specialized secure systems for specific application areas; interoperability, and composition. \end{equation}\] Security Technologies: authentication; authorization models and mechanisms; auditing and intrusion detection; cryptographic algorithms, protocols, services, and infrastructure; recovery and survivable operation; risk analysis; assurance including cryptanalysis and formal methods; penetration technologies including viruses, Trojan horses, spoofing, sniffing, cracking, and covert channels. After \( x_2 \) is emitted a key change is initiated. Due to lack of support for the GMP library and the BIGNUM primitive in the versions of SSL supported in the M3 device, ElGamal and Paillier cannot be implemented using GMP or SSL. Q1 simply counts the number of readings and performs at 96% throughput of plaintext stream. Fig. Operations across groups. Deterministic encryption (DET) is implemented using an AES pseudo-random permutation block cipher with a variant of CMC mode [27] with a zero initialization vector. To reduce ciphertext size overhead, C3PO adapts a technique introduced by Ge et al. In this section, we analyze threats across various system components of C3PO such as IoT devices, cloud nodes, trusted tier, and the network and describe how C3PO addresses these threats. Similarly, equality comparisons, order comparisons, and search over encrypted data operations require non-trivial computations over the ciphertexts. . The ACM Conflict of Interest (COI) Policy describes what a COI is, who is responsible for being aware of such conflicts, how to manage COIs, and how to report violations. SecureScala [28] is a domain-specific language in Scala that allows expressing secure programs without requiring any cryptographic knowledge from the programmer.