4 research outputs found
A First-Order SCA Resistant AES without Fresh Randomness
Since the advent of Differential Power Analysis (DPA) in the late 1990s protecting embedded devices against Side-Channel Analysis (SCA) attacks has been a major research effort. Even though many different first-order secure masking schemes are available today, when applied to the AES S-box they all require fresh random bits in every evaluation. As the quality criteria for generating random numbers on an embedded device are not well understood, an integrated Random Number Generator (RNG) can be the weak spot of any protected implementation and may invalidate an otherwise secure implementation. We present a new construction based on Threshold Implementations and Changing of the Guards to realize a first-order secure AES with zero per-round randomness. Hence, our design does not need a built-in RNG, thereby enhancing security and reducing the overhead
CPA on Hardware Implementation of COLM Authenticated Cipher and Protect it with DOM Masking Scheme
Authenticated encryption schemes provide both confidentiality and integrity services, simultaneously. Correlation power analysis (CPA) can be a thread for authenticated ciphers, like all physical implementations of any cryptographic system. In this paper, for the first time, a three-steps CPA attack against COLM, one of the winners of CAESAR, is presented to indicate its vulnerability. For this purpose, in this research paper, this authenticated encryption scheme is implemented on the FPGA of the SAKURA-G board and, by measuring and collecting 1,800 power traces, a successful CPA attack with zero value power model has been mounted on it. In addition, a protected hardware architecture for the COLM is proposed to make this design secure against first-order CPA attacks. To this end, a domain-oriented masking (DOM) scheme with two inputs/outputs share is used to protect the COLM. To verify the security of these countermeasures, we mounted a first and second-order CPA attack and a non-specified t-test on the protected COLM
SoK: Design Tools for Side-Channel-Aware Implementations
Side-channel attacks that leak sensitive information through a computing
device's interaction with its physical environment have proven to be a severe
threat to devices' security, particularly when adversaries have unfettered
physical access to the device. Traditional approaches for leakage detection
measure the physical properties of the device. Hence, they cannot be used
during the design process and fail to provide root cause analysis. An
alternative approach that is gaining traction is to automate leakage detection
by modeling the device. The demand to understand the scope, benefits, and
limitations of the proposed tools intensifies with the increase in the number
of proposals.
In this SoK, we classify approaches to automated leakage detection based on
the model's source of truth. We classify the existing tools on two main
parameters: whether the model includes measurements from a concrete device and
the abstraction level of the device specification used for constructing the
model. We survey the proposed tools to determine the current knowledge level
across the domain and identify open problems. In particular, we highlight the
absence of evaluation methodologies and metrics that would compare proposals'
effectiveness from across the domain. We believe that our results help
practitioners who want to use automated leakage detection and researchers
interested in advancing the knowledge and improving automated leakage
detection
ELM : A Low-Latency and Scalable Memory Encryption Scheme
Memory encryption with an authentication tree has received significant attentions due to the increasing threats of active attacks and the widespread use of non-volatile memories. It is also gradually deployed to real-world systems, as shown by SGX available in Intel processors. The topic of memory encryption has been recently extensively studied, most actively from the viewpoint of system architecture. In this paper, we study the topic from the viewpoint of provable secure symmetric-key designs, with a primal focus on latency which is an important criterion for memory. A progress in such a direction can be observed in the memory encryption scheme inside SGX (SGX integrity tree or SIT). It uses dedicated, low-latency symmetric-key components, i.e., a message authentication code (MAC) and an authenticated encryption (AE) scheme based on AES-GCM. SIT has an excellent latency, however, it has a scalability issue for its on-chip memory size. By carefully examining the required behavior of MAC and AE schemes and their interactions in the tree operations, we develop a new memory encryption scheme called ELM. It consists of fully-parallelizable, low-latency MAC and AE schemes and utilizes an incremental property of the MAC. Our AE scheme is similar to OCB, however it improves OCB in terms of decryption latency. To showcase the effectiveness, we consider instantiations of ELM using the same cryptographic cores as SIT, and show that ELM has significantly lower latency than SIT for large memories. We also conducted preliminary hardware implementations to show that the total implementation size is comparable to SIT