Broken schemes in last release

[adelapie]

Hello,

At CT-RSA 2021 Venema and Alpar presented attacks against 11 ABE schemes and two of them are implemented in the last version of CHARM: DAC-MACS and MA-ABE-YJ14:

• https://jhuisi.github.io/charm/charm/schemes/abenc/abenc_dacmacs_yj14.html
• https://jhuisi.github.io/charm/_modules/abenc_maabe_yj14.html

Moreover, the YCT14 scheme was broken in 2019 and is also implemented in CHARM: https://github.com/JHUISI/charm/blob/dev/charm/schemes/abenc/abenc_yct14.py

It is possible to mount decryption attacks against them.

References:

https://eprint.iacr.org/2020/460 https://www2.hci.uni-hannover.de/papers/Tan2019.pdf