A New Partial Key Exposure Attack on Multi-power RSA, by Muhammed F. Esgin and Mehmet S. Kiraz and Osmanbey Uzunkol

An important attack on multi-power RSA ($N=p^rq$) was introduced by Sarkar in 2014, by extending the small private exponent attack of Boneh and Durfee on classical RSA. In particular, he showed that $N$ can be factored efficiently for $r=2$ with private exponent $d$ satisfying $d