Abstract: A flow through asynchronous elastic first-in, first-out (FIFO) apparatus and method are provided for implementing multi-engine parsing and authentication. A FIFO random access memory (RAM) has a data input for receiving data and control information and a data output for outputting the data and control information. The FIFO RAM includes a plurality of locations for storing a plurality of words, each word including a set number of bits. Write clocked logic is provided for loading the data and control information to the FIFO RAM at a first clock frequency. Asynchronous read clocked logic is provided for outputting the data and control information from the FIFO RAM at a second clock frequency. The first clock frequency of the write clocked logic and the second clock frequency of the asynchronous read clocked logic and a data width of the FIFO RAM are selectively provided for outputting the data and control information from the FIFO RAM with no back pressure.