• Analysis of Trivium Using Compressed Right Hand Side Equations 

      Schilling, Thorsten Ernst; Raddum, Håvard (Chapter; Peer reviewed, 2012)
      We study a new representation of non-linear multivariate equations for algebraic cryptanalysis. Using a combination of multiple right hand side equations and binary decision diagrams, our new representation allows a very ...
    • On the IND-CCA1 Security of FHE Schemes 

      Hovd, Martha Norberg; Fauzi, Prastudy; Raddum, Håvard (Journal article; Peer reviewed, 2022)
      Fully homomorphic encryption (FHE) is a powerful tool in cryptography that allows one to perform arbitrary computations on encrypted material without having to decrypt it first. There are numerous FHE schemes, all of which ...
    • A Practical Adaptive Key Recovery Attack on the LGM (GSW-like) Cryptosystem 

      Fauzi, Prastudy; Hovd, Martha Norberg; Raddum, Håvard (Chapter, 2021)
      We present an adaptive key recovery attack on the leveled homomorphic encryption scheme suggested by Li, Galbraith and Ma (Provsec 2016), which itself is a modification of the GSW cryptosystem designed to resist key recovery ...
    • Solving Compressed Right Hand Side Equation Systems with Linear Absorption 

      Schilling, Thorsten Ernst; Raddum, Håvard (Chapter; Peer reviewed, 2012)
      In this paper we describe an approach for solving complex multivariate equation systems related to algebraic cryptanalysis. The work uses the newly introduced Compressed Right Hand Sides (CRHS) representation, where equations ...
    • Solving Equation Systems by Agreeing and Learning 

      Schilling, Thorsten Ernst; Raddum, Håvard (Chapter; Peer reviewed, 2010)
      We study sparse non-linear equation systems defined over a finite field. Representing the equations as symbols and using the Agreeing algorithm we show how to learn and store new knowledge about the system when a ...