See https://gist.github.com/Neo23x0/6af876ee72b51676c82a2db8d2cd3639 as a base64 cheat sheet. The clas­sic (base64 com­bines the bytes of the text and sep­a­rates 6 bit (2^6 = 64) and maps each 6 bit to a char­ac­ter. “=” means “two byte miss­ing”. For exam­ple, if the com­bined strings have 2 bit “left” (41.…), then (A==) echo Hi | base64 -d Con­vert hex…