I am mostly self taught and have limited knowledge of the symbology in the image below. It is a diagram of a sub block the RIPEMD-160 algorithm:
Are such symbols standardized? Is there a good dictionary or atlas someone is aware of that could link such symbols to their definitions?
Here is the source: https://en.wikipedia.org/wiki/RIPEMD
It is RIPEMD-160 and the paper describes them as;
$f$ represents nonlinear functions at bit level: $exor, mux, -, mux, -$ and varies with rounds;
$\boxplus$ denotes addition modulo $2^{32}$
$rol_s$ denotes cyclic left shift (rotate) over $s$ positions. in the figure there is one fixed 10 and one variable with $s[i]$
I don't know of a glossary for symbols on these diagrams, however in this case:
$f$ is some sbox, that is, some lookup table (and whose details must be given somewhere else in the document where this image is found)
$\boxplus$ is either modular addition (modulo $2^w$, where $w$ is the number of bits in each line) or bit-wise exclusive-or. Most typically, it is modular addition; however that usage is commonly used in conjunction with $\oplus$; hence the alterative meaning is possible.
$<<$ is left-wise rotate, where each bit is moved a number of locations to the left and if a bit goes past the top of the word, it wraps around to the bottom; the number of locations each bit moves is either $s[i]$ or the fixed value 10 (as shown in the diagram). Now, $<<$ more commonly refers to a left-wise shift, where bits going past the top of the word are discarded, and we insert zeros on the right; however that would not make sense in this context.
The document this diagram came from should give more details...
