The 1600-bit state is represented as a 5×5 matrix of 64-bit words (Little Endian). The SHA3 algorithms are considered the successors of the SHA2 family.

A permutation consists of 24 rounds of the steps θ (theta), ρ (rho), π (pi), χ (chi), and ι (iota). For clarity: θ mixes column parities, ρ rotates bits, π permutes the positions, χ provides nonlinearity, and ι adds the round constant. Further details can be found here.

In principle, the functions are invertible. However, since only the first 256 of the 1600 bits are taken at the end, the procedure becomes a one-way function.

For illustration and demonstration purposes, the processing steps were reimplemented in Excel. To keep it compact, only a 5×5 state was used, which limits the maximum input length to 134 characters. The following image shows an example processing.

Download the Microsoft Excel file. Macros were omitted; however, due to the use of lambda functions, the result will only work under Office 365 or Excel 2024.

^{SHA256: 3139C41135C50C2469F9599782345E40A4E8247AE95FCE4482F6F40122C4F1D4}