bitsliced

Bitsliced refers to a technique used in cryptography and digital signal processing. It involves processing data in small, fixed-size chunks, typically on a bit-by-bit basis or in small groups of bits. This approach can offer advantages in certain computational scenarios, particularly when dealing with hardware implementations or when specific algorithmic structures are beneficial.

The core idea of bitslicing is to break down an operation, such as an encryption algorithm, into a series of operations on individual bits or small bit slices. Instead of processing a whole byte or word at a time, the computation is performed in parallel across all the bits of the input data. This can lead to increased efficiency, especially on architectures that can efficiently perform bitwise operations in parallel.

One of the primary applications of bitslicing is in the implementation of symmetric-key cryptographic algorithms like AES. By representing the internal state of the cipher as a collection of bit slices, computations can be performed in a way that is resistant to certain side-channel attacks, such as power analysis. This is because the operations on individual bits can be made more uniform, obscuring the correlation between the computation and the power consumed.

Bitslicing can also be used in other areas where bitwise manipulation is prevalent. For example, in certain image processing filters or in the design of specialized hardware accelerators. The effectiveness of bitslicing often depends on the specific algorithm and the underlying hardware architecture, as it requires careful design to exploit parallel bitwise operations effectively.