Revisiting Randomness Extraction and Key Derivation Using the CBC and Cascade Modes

Niranjan Balachandran; Ashwin Jha; Mridul Nandi; Soumit Pal

doi:10.46586/tosc.v2023.i4.391-419

Revisiting Randomness Extraction and Key Derivation Using the CBC and Cascade Modes

Authors

Niranjan Balachandran Indian Institute of Technology Bombay, Mumbai, India
Ashwin Jha CISPA Helmholtz Center for Information Security, Saarbrücken, Germany
Mridul Nandi Indian Statistical Institute, Kolkata, India
Soumit Pal Indian Statistical Institute, Kolkata, India

DOI:

https://doi.org/10.46586/tosc.v2023.i4.391-419

Keywords:

CBC-MAC, cascade construction, tight bound, missing proofs

Abstract

In this paper, we revisit a celebrated result by Dodis et al. from CRYPTO 2004, in relation with the suitability of CBC-MAC and cascade construction for randomness extraction. We first observe that the proof of three key sub-results are missing in the paper, which makes it difficult to verify the authors’ claims. Then, using a detailed and thorough analysis of the collision probability for both the CBC function and the cascade construction, we provide the missing proofs, thereby establishing the veracity of this old result. As a side-effect, we have made a significant advancement in the characterization of graph-based analysis of CBC and cascade construction, which could be of independent interest.

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Published

2023-12-08

How to Cite

Balachandran, N., Jha, A., Nandi, M., & Pal, S. (2023). Revisiting Randomness Extraction and Key Derivation Using the CBC and Cascade Modes. IACR Transactions on Symmetric Cryptology, 2023(4), 391–419. https://doi.org/10.46586/tosc.v2023.i4.391-419