PIPO: A Lightweight Block Cipher with Efficient Higher-Order Masking Software Implementations.

In this paper, we introduce a new lightweight 64-bit block cipher PIPO (PIPO stands for “Plug-In” and “Plug-Out”, representing its use in side-channel protected and unprotected environments, respectively.) supporting a 128 or 256-bit key. It is a byte-oriented and bitsliced cipher that offers excellent performance in 8-bit AVR software implementations. In particular, PIPO allows for efficient higher-order masking implementations, since it uses a minimal number of nonlinear operations. Our implementations demonstrate that PIPO outperforms existing block ciphers (for the same block and key lengths) in both side-channel protected and unprotected environments, on an 8-bit AVR. Furthermore, PIPO records competitive round-based hardware implementations.