Software Implementation of OCB Mode

Authenticated Encryption Modes of Block Ciphers, Their Security and Implementation Properties

In this thesis, four authenticated encryption modes of operation are presented, namely, GCM mode, CCM* mode, OCB mode and CWC mode. These modes can provide confidentiality and authenticity simultaneously. The GCM mode and CCM* mode are in detail introduced. And it shows the comparison of the four modes from different aspects: properties, security, and performance in hardware implementation and ...

The Software Performance of Authenticated-Encryption Modes

We study the software performance of authenticated-encryption modes CCM, GCM, and OCB. Across a variety of platforms, we find OCB to be substantially faster than either alternative. For example, on an Intel i5 (“Clarkdale”) processor, good implementations of CCM, GCM, and OCB encrypt at around 4.2 cpb, 3.7 cpb, and 1.5 cpb, while CTR mode requires about 1.3 cpb. Still we find room for algorithm...

Collision attacks on OCB

We show that collision attacks are quite effective on the OCB block cipher mode. When a collision occurs OCB loses its authentication capability. To keep adequate authentication security OCB has to be limited in the amount of data it processes. This restriction is relevant to real-life applications, and casts doubt on the wisdom of using OCB.

An FPGA implementation of the AES-Rijndael in OCB/ECB modes of operation

Implementation in one FPGA of the AES-Rijndael in Offset Codebook (OCB) and Electronic Codebook (ECB) modes of operation was developed and experimentally tested using the Insight Development Kit board, based on Xilinx Virtex II XC2V1000-4 device. The circuit was designed to provide simultaneous data privacy and authenticity in applications which require small area such as wireless LANs, cellula...

OCB Mode 11