Paper 2019/086
Reinterpreting and Improving the Cryptanalysis of the Flash Player PRNG
George Teseleanu
Abstract
Constant blinding is an efficient countermeasure against just-in-time (JIT) spraying attacks. Unfortunately, this mitigation mechanism is not always implemented correctly. One such example is the constant blinding mechanism found in the Adobe Flash Player. Instead of choosing a strong mainstream pseudo-random number generator (PRNG), the Flash Player designers chose to implement a proprietary one. This led to the discovery of a vulnerability that can be exploited to recover the initial seed used by the PRNG and thus, to bypass the constant blinding mechanism. Using this vulnerability as a starting point, we show that no matter the parameters used by the previously mentioned PRNG it still remains a weak construction. A consequence of this study is an improvement of the seed recovering mechanism from previously known complexity of $\mathcal O(2^{21})$ to one of $\mathcal O(2^{11})$.
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- Published elsewhere. Minor revision. C2SI-2019
- Keywords
- jit spaying attacksflash player prngconstant blinding
- Contact author(s)
- george teseleanu @ yahoo com
- History
- 2022-03-15: revised
- 2019-01-28: received
- See all versions
- Short URL
- https://ia.cr/2019/086
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2019/086,
author = {George Teseleanu},
title = {Reinterpreting and Improving the Cryptanalysis of the Flash Player {PRNG}},
howpublished = {Cryptology {ePrint} Archive, Paper 2019/086},
year = {2019},
url = {https://eprint.iacr.org/2019/086}
}
