Cipher

About: Cipher is a research topic. Over the lifetime, 9409 publications have been published within this topic receiving 110309 citations. The topic is also known as: cypher & cryptographic algorithm.

Method and apparatus for data security and automatic repeat request implementation in a wireless communication system

Abstract: A method and apparatus for implementing data security and automatic repeat request (ARQ) in a wireless communication system are disclosed. Cipher entities are included in a wireless transmit/receive unit (WTRU) and an access gateway (aGW), and outer ARQ, (or radio link control (RLC)), entities are included in the WTRU and an evolved Node-B (eNode-B). Each cipher entity is located on top of an outer ARQ entity. The cipher entities cipher and decipher a data block by using a generic sequence number (SN) assigned to the data block. The outer ARQ entities may segment the ciphered data block to multiple packet data units (PDUs), may concatenate multiple ciphered data blocks to a PDU, or may generate one PDU from one data block. The outer ARQ entities may segment or re-segment the PDU when a transmission failure occurs.

Application of dynamic variable cipher security certificate in Internet of Things

Abstract: With the development of Internet of Things (IOT), there are more and more concerns about the security of IOT. In terms of security of Internet, the security framework of Internet can not provide a completely solution to solve all security problems in IOT [1]. This paper describes the security structure of sensor layer, network layer, and application layer in IOT. This thesis intends to analyze the security features of sensor layer, and then presents dynamic variable cipher security certificate, a new method of ID authentication among node and node in sensor layer. This certificate provides a method of “one time one cipher” between communicating parties. It's a lightweight encryption or decryption method, using time stamp technology, timeliness in the two communication partners is guaranteed. In general, dynamic variable cipher security certificate can be well applied to the communication among sensor nodes in IOT.

A New Attack on 6-Round IDEA

Abstract: IDEA is a 64-bit block cipher with 128-bit keys introduced by Lai and Massey in 1991. IDEA is one of the most widely used block ciphers, due to its inclusion in several cryptographic packages, such as PGP. Since its introduction in 1991, IDEA has withstood extensive cryptanalytic effort, but no attack was found on the full (8.5-round) variant of the cipher. In this paper we present the first known attack on 6-round IDEA faster than exhaustive key search. The attack exploits the weak keyschedule algorithm of IDEA, and combines Square-like techniques with linear cryptanalysis to increase the number of rounds that can be attacked. The attack is the best known attack on IDEA. We also improve previous attacks on 5-round IDEA and introduce a 5-round attack which uses only 16 known plaintexts.

Message Concealment Techniques using Image based Steganography

Abstract: Image based steganography is the most popular method for message concealment. In this paper, two techniques are proposed for enhancing the message secrecy using image based steganography. The first technique is based on the use of punctuation marks to encode a secret message before embedding it into the image file. The second technique is based on the use of modified scytale cipher to hide a secret message in an image file. Both of these techniques have been implemented and tested using the S-Tools software package. The original and stego-images both are shown for the purpose of comparison

Cryptanalysis of the FLIP Family of Stream Ciphers

Abstract: At Eurocrypt 2016, Meaux et al. proposed FLIP, a new family of stream ciphers intended for use in Fully Homomorphic Encryption systems. Unlike its competitors which either have a low initial noise that grows at each successive encryption, or a high constant noise, the FLIP family of ciphers achieves a low constant noise thanks to a new construction called filter permutator. In this paper, we present an attack on the early version of FLIP that exploits the structure of the filter function and the constant internal state of the cipher. Applying this attack to the two instantiations proposed by Meaux et al. allows for a key recovery in $$2^{54}$$ basic operations resp. $$2^{68}$$, compared to the claimed security of $$2^{80}$$ resp. $$2^{128}$$.