BranchScope: A New Side-Channel Attack on Directional Branch Predictor

By Dmitry Evtyushkin, Ryan D. Riley, Nael B. Abu-Ghazaleh, Dmitry V. Ponomarev. International Conference on Architectural Support for Programming Languages and Operating Systems, 2018

334 citations recorded by the source corpus.

We present BranchScope - a new side-channel attack where the attacker infers the direction of an arbitrary conditional branch instruction in a victim program by manipulating the shared directional branch predictor. The directional component of the branch predictor stores the prediction on a given branch (taken or not-taken) and is a different component from the branch target buffer (BTB) attacked by previous work. BranchScope is the first fine-grained attack on the directional branch predictor, expanding our understanding of the side channel vulnerability of the branch prediction unit. Our attack targets complex hybrid branch predictors with unknown organization. We demonstrate how an attacker can force these predictors to switch to a simple 1-level mode to simplify the direction recovery. We carry out BranchScope on several recent Intel CPUs and also demonstrate the attack against an SGX enclave.

Subfields: Artificial Intelligence, Hardware and Architecture, Signal Processing

View Paper: https://www.semanticscholar.org/paper/e3d8c6cf9109b262d4c5275f2254e2427ee48a88

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

1. Mohammadkazem Taram
2. Dean M. Tullsen
3. Brandon Lucia
4. Ashish Venkat
5. Hadi Esmaeilzadeh

In Hardware and Architecture

1. Bradley Denby
2. Brandon Lucia
3. Dean M. Tullsen
4. Mohammadkazem Taram
5. Onur Mutlu
6. Thomas Moscibroda

In Signal Processing

1. Mohammadkazem Taram
2. Dean M. Tullsen
3. Ashish Venkat
4. Hadi Esmaeilzadeh

Citations in the corpus

• Foreshadow: Extracting the Keys to the Intel SGX Kingdom with Transient Out-of-Order Execution (2018, neutral): “This point has been repeatedly demonstrated in the form of a steady stream of highresolution PRIME+PROBE CPU cache [6,12,17,23,46,51] and branch prediction [13, 39] attacks against SGX enclaves.”
• Orbital Edge Computing: Nanosatellite Constellations as a New Class of Computer System (2020, background): “Edge processing avoids the privacy and security risks of multi-tenant infrastructures in shared datacenters [26, 56, 60].”
• Context-Sensitive Fencing: Securing Speculative Execution via Microcode Customization (2019, background): “mizations such as caches, branch speculation, memory disambiguation, and even DVFS, through side-channels such as memory bus activity [4], power consumption characteristics [8], branch access patterns [2, 29], faults [47, 40], acoustics [33, 32], electromagnetic effects [30], functional unit timing ”