This paper presents a new DNA cryptographic system based on IBROS Cypher. IBROS mainly deals with manipulation in the binary form of the plain text message to encrypt and decrypt it. IBROS uses a completely randomized two key system, which makes it hard to break. Even after such complex methods, the applicability of each method is simple which makes it a fast DNA cryptography system. IBROS is an abbreviation for the five steps used in this cypher. They are – ICFM (Index Comparison Flip Mutation), BFM (Bit Flip Mutation), RFS (Rail Fence Straightening), OMB (One-to-Many Breeding), and Swap Mutation. All of these five steps are inspired from different fields of computing and cryptography, yet they are completely unique as cryptographic method. ICFM is inspired by the working principles of a Turing Machine, whereas BFM, OMB, and Swap Mutation are inspired by Genetic Algorithms, the method named RFS is a modified form of the traditional Rail Fence Cypher. IBROS works by taking the binary form of the plain text message, then passing it through each step serially, and finally encoded in to DNA bases using one of the eight rules of DNA encoding. Some of the presented methods in IBROS can be used not only for binary data but also for normal text data. This new technique will prove to be promising in the field of DNA computing.