Systems, methods, and computer-readable media are disclosed for performing message padding of input messages in a manner that preserves the integrity of the input data regardless of whether the input message is in a bit-oriented format or a bit-reversed format. Each byte of a partial input message block of an input message may be converted from a bit-reversed format to a bit-oriented format prior to performing message padding in order to ensure that input data bits are not lost during the message padding. Subsequent to the message padding that generates one or more padded message blocks, the padded message block(s) may be converted from a bit-oriented format to a bit-reversed format to enable further processing of the input message to be performed to obtain a message digest.