Ray A. Perlner, Albrecht R. Petzoldt, Daniel C. Smith-Tone
Multivariate Public Key Cryptography (MPKC) is one of the main candidates for secure communication in a post-quantum era. Recently, Yasuda and Sakurai proposed in  a new multivariate encryption scheme called SRP, which combines the Square encryption scheme with the Rainbow signature scheme and the Plus modifier. In this paper we propose a practical key recovery attack against the SRP scheme, which is based on the min-Q-rank property of the system. Our attack is very efficient and allows us to break the parameter sets recommended in  within minutes. Our attack shows that combining a weak scheme with a secure one does not automatically increase the security of the weak scheme.
, Petzoldt, A.
and Smith-Tone, D.
Total Break of the SRP Encryption Scheme, Selected Areas in Cryptography (SAC 2017), Ottowa, -1, [online], https://doi.org/10.1007/978-3-319-72565-9_18
(Accessed September 22, 2023)