@InProceedings{PQCRYPTO:FHLRT26,
  author="Fouotsa, Tako Boris
  and Houben, Marc
  and Lorenzon, Gioella
  and Rueger, Ryan
  and Tasbihgou, Parsa",
  editor="Bardet, Magali
  and Niederhagen, Ruben",
  title="On the Active Security of the PEARL-SCALLOP Group Action",
  booktitle="Post-Quantum Cryptography",
  year="2026",
  publisher="Springer Nature Switzerland",
  address="Cham",
  pages="74--104",
  abstract="We present an active attack against the PEARL-SCALLOP group action. Modelling Alice as an oracle that outputs the action by a secret ideal class on suitably chosen oriented elliptic curves, we show how to recover the secret using a handful of oracle calls (four for the parameter set targeting a security level equivalent to CSIDH-1024), by reducing to the computation of moderately-sized group action discrete logarithms. The key ingredient to the attack is to employ curves with non-primitive orientations inherent to the PEARL-SCALLOP construction. We provide methods for public-key validation---that is, for deciding whether a given orientation is primitive---and discuss their practicality.",
  isbn="978-3-032-22698-3"
}