A survey of survivability in mobile ad hoc networks <s> 1) SPREAD: <s> An Information Dispersal Algorithm (IDA) is developed that breaks a file F of length L = u F u into n pieces F i , l ≤ i ≤ n , each of length u F i u = L / m , so that every m pieces suffice for reconstructing F . Dispersal and reconstruction are computationally efficient. The sum of the lengths u F i u is ( n / m ) · L . Since n / m can be chosen to be close to l, the IDA is space efficient. IDA has numerous applications to secure and reliable storage of information in computer networks and even on single disks, to fault-tolerant and efficient transmission of information in networks, and to communications between processors in parallel computers. For the latter problem provably time-efficient and highly fault-tolerant routing on the n -cube is achieved, using just constant size buffers. <s> BIB001 </s> A survey of survivability in mobile ad hoc networks <s> 1) SPREAD: <s> A channel coding approach called diversity coding is introduced for self-healing and fault-tolerance in digital communication networks for nearly instantaneous recovery from link failures. To achieve this goal, the problem of link failures is treated as an erasure channel problem. Implementation details of this technique in existing and future communication networks are discussed. > <s> BIB002
The Secure Protocol for Reliable Data Delivery (SPREAD) scheme proposes the use of some techniques to enhance data confidentiality and data availability. Initially, messages are split into multiple pieces by the source node, using the threshold secret sharing scheme. Each piece is encrypted and sent out via multiple independent paths. Encryption between neighboring nodes with a different key is assumed as well as the existence of an efficient key management scheme. SPREAD focuses on three main operations: to divide the message, to select multiple paths and to allocate message pieces into paths. Messages are split by the threshold secret sharing algorithm  and each piece is allocated into a selected path aiming to minimize the probability of harm. SPREAD selects multiple independent paths taking into account security factors such as the probability of being compromised. The goal of SPREAD is to achieve an optimal share allocation way, where the attacker should damage all the paths to recover the message. 2) SMT: The goal of the secure message transmission (SMT) protocol is to ensure data confidentiality, data integrity, and data availability, safeguarding the end-to-end transmission against malicious behavior of intermediary nodes. SMT exploits four main characteristics: end-to-end secure and secure feedback mechanism, dispersion of the transmitted data, simultaneous usage of multiple paths, and adaptation to the network changing conditions. It requires a security association (SA)  between the two end communicating nodes, so no link encryption is needed. This trust relationship is indispensable for providing data integrity and authentication of end nodes, necessary for any secure communication scheme. The two end nodes make use of a set of node-disjoint paths, called Active Path Set (APS), being a subset of all existing paths between them. Data message is broken into several small pieces by the information dispersal scheme BIB001 . Data redundancy is added to allow recovery, being also divided into pieces. All pieces are sent through different routes existent in APS, enhancing statistically the confidentiality and availability of exchanged messages. At the destination, the dispersed message is successfully reconstructed only if a sufficient number of pieces are received. Each piece carries a Message Authentication Code (MAC), allowing its integrity verification by the destination. The destination validates the incoming pieces and acknowledges the successfully received ones thought a feedback to the source. The feedback mechanism is also protected by cryptography and is dispersed to provide fault tolerance. Each path of APS has a reliability rate calculated by the number of successful and unsuccessful transmissions on this path. SMT uses this rate to manage the paths in APS, trying to determine and maintain a maximally secure path-set, and adjusting its parameters to remain effective and efficient. 3) SDMP: The Secured Data based MultiPath (SDMP) protocol exploits also multiple paths between network nodes to increase the robustness and data confidentiality. The protocol assumes Wired Equivalent Privacy (WEP) link encryption/decryption of all the frames between neighboring nodes, which provide link layer confidentiality and authentication. SDMP can work with any routing protocol which provides topology discovery and supports the use of multipath for routing. SDMP distinguishes between two types of path: signaling and data. Signaling type requires only one path of the path-set existent between source and destination nodes, being the other paths available for data transmission. The protocol divides the message into pieces using the Diversity Coding approach BIB002 . Each piece has a unique identifier and all of them are combined in pairs through an XOR operation related to a random integer number. Each pair is sent along a different path. All information necessary for message reconstruction at the destination is sent by the signaling path. Unless the attacker can gain access to all of the transmitted parts, the probability of message reconstruction is low. That is, to compromise the confidentiality of the original message, the attacker must get within eavesdropping range of the source/destination, or simultaneously listen on all the paths used and decrypt the WEP encryption of each transmitted part. However, it is possible to deduce parts of the original message from only a few of the transmitted pieces, especially since one piece of the original message is always sent in its original form on one of the paths.