Generic Side-channel attacks on CCA-secure lattice-based PKE and KEMs

Transactions on Cryptographic Hardware and Embedded Systems

Sujoy Sinha Roy¹  Anupam Chattopadhyay²  Prasanna Ravi³  Shivam Bhasin³ 

[1] School of Computer Science and Engineering, Nanyang Technological University, Singapore;School of Computer Science, University of Birmingham, United Kingdom;Temasek Laboratories, Nanyang Technological University, Singapore;

关键词: Lattice-based cryptography;    EM-based side-channel attack;    LWE/LWR;    Chosen Ciphertext Attack;    Public Key Encryption;    Key Encapsulation Mechanism;   

DOI  :  10.13154/tches.v2020.i3.307-335

来源: DOAJ

【 摘 要 】

In this work, we demonstrate generic and practical EM side-channel assisted chosen ciphertext attacks over multiple LWE/LWR-based Public Key Encryption (PKE) and Key Encapsulation Mechanisms (KEM) secure in the chosen ciphertext model (IND-CCA security). We show that the EM side-channel information can be efficiently utilized to instantiate a plaintext checking oracle, which provides binary information about the output of decryption, typically concealed within IND-CCA secure PKE/KEMs, thereby enabling our attacks. Firstly, we identified EM-based side-channel vulnerabilities in the error correcting codes (ECC) enabling us to distinguish based on the value/validity of decrypted codewords. We also identified similar vulnerabilities in the Fujisaki-Okamoto transform which leaks information about decrypted messages applicable to schemes that do not use ECC. We subsequently exploit these vulnerabilities to demonstrate practical attacks applicable to six CCA-secure lattice-based PKE/KEMs competing in the second round of the NIST standardization process. We perform experimental validation of our attacks on implementations taken from the open-source pqm4 library, running on the ARM Cortex-M4 microcontroller. Our attacks lead to complete key-recovery in a matter of minutes on all the targeted schemes, thus showing the effectiveness of our attack.

【 授权许可】

Unknown