Timing attack

About: Timing attack is a research topic. Over the lifetime, 726 publications have been published within this topic receiving 25462 citations.

Timing attack protection in a cryptographic processing system

Abstract: Apparatus and method for enacting data security in a cryptographic processing system, such as a data storage device. In some embodiments, a timer circuit is initiated to denote an elapsed time interval of predetermined duration responsive to a function call by an initiator circuit to perform a selected cryptographic function upon input data. The selected cryptographic function is executed to generate output data which are temporarily stored in a memory location during a waiting period prior to a conclusion of the elapsed time interval. Additional functions may be performed during the waiting period. A notification from the timer circuit is received at the conclusion of the elapsed time interval, and the output data are transferred from the memory to the initiator circuit. In this way, a timing attack may be defended against by configuring the selected cryptographic function to have the same overall execution time for different input data sets.

Information-flow attacks based on limited observations

Abstract: Two formal models for description of timing attacks are presented, studied and compared with other security concepts. The models are based on a timed process algebra and on a concept of observations which make visible only a part of a system behaviour. An intruder tries to deduce some private system activities from this partial information which contains also timing of actions. To obtain realistic security characterizations some limitations on observational power of the intruder are applied. It is assumed that the intruder has only limited time window to perform the attack or time of action occurrences can be measured only with a given limited precision.

Timing attacks on PIN input in VoIP networks

Abstract: To access automated voice services, Voice over IP (VoIP) users sometimes are required to provide their Personal Identification Numbers (PIN) for authentication. Therefore when they enter PINs, their user-agents generate packets for each key pressed and send them immediately over the networks. This paper shows that a malicious intermediary can recover the inter-keystroke time delay for each PIN input even if the standard encryption mechanism has been applied. The inter-keystroke delay can leak information of what has been typed: Our experiments show that the average search space of a brute force attack on PIN can be reduced by around 80%.

A Timing Attack on Blakley's Modular Multiplication Algorithm, and Applications to DSA

Abstract: In this paper, we introduce a timing attack scheme against a 160-bit modular multiplication with Blakley's algorithm. It is assumed that a set of public inputs are multiplied by a secret parameter and running time of each multiplication is given, but the multiplication result is not known and a machine similar to victim machine isn't available. The proposed attack extracts all 160 bits of the secret parameter. Running time of Blakley's algorithm is analyzed and it is shown that running time of each step is dependent on the running time of other steps. The dependencies make the parameters of the attack be dependent on the secret key, while it makes the attack rather complicated. A heuristic algorithm is used to find the parameters of the attack. As a real scenario, the attack is applied against on-line implementation of Digital Signature Algorithm, which employs Blakley's modular multiplication. Practical results show that secret key of DSA will be found using 1,000,000 timing samples.

Analysis of Mitigation Measures for Timing Attacks in Mobile-Cloud Offloading Systems

Abstract: Mobile cloud offloading has been proposed to migrate complex computations from mobile devices to powerful servers. While this may be beneficial from the performance and energy perspective, it certainly exhibits new challenges in terms of security due to increased data transmission over networks with potentially unknown threats. Among possible security issues are timing attacks which are not prevented by traditional cryptographic security. Usually random delays are introduced in such systems as a popular countermeasure. Random delays are easily deployed even if the source code of the application is not at hand. While the benefits are obvious, a random delay introduces a penalty that should be minimized. The challenge is to select the distribution from which to draw the random delays and to set mean and variance in a suitable way such that the system security is maximized and the overhead is minimized. To tackle this problem, we have implemented a prototype that allows us to compare the impact of different random distributions on the expected success of timing attacks. Based on our model, the effect of random delay padding on the performance and security perspective of offloading systems is analyzed in terms of response time and optimal rekeying rate. We found that the variance of random delays is the primary influencing factor to the mitigation effect. Based on our approach, the system performance and security can be improved as follows. Starting from the mission time of a computing job one can select a desired padding policy. From this the optimal rekeying interval can be determined for the offloading system.