The use of cryptographic hash functions like MD5 or SHA for message authentication has become a standard approach inmanyInternet applications and protocols. Though very easy to implement, these mechanisms are usually based on ad hoc techniques that lack a sound security analysis. We present new constructions of message authentication schemes based on a cryptographic hash function. Our schemes, NMAC and HMAC, are proven to be secure as long as the underlying hash function has some reasonable cryptographic strengths. Moreover we show, in a quantitativeway, that the schemes retain almost all the security of the underlying hash function. In addition our schemes are e cient and practical. Their performance is essentially that of the underlying hash function. Moreover they use the hash function (or its compression function) as a black box, so that widely available library code or hardware can be used to implement them in a simple way, and replaceability of the underlying hash function is easily supported.

There are well-known techniques for message authentication using universal hash functions. This approach seems very promising, as it provides schemes that are both efficient and provably secure under reasonable assumptions. This paper contributes to this line of research in two ways. First, it analyzes the basic construction and some variants under more realistic and practical assumptions. Second, it shows how these schemes can be efficiently implemented, and it reports on the results of empirical performance tests that demonstrate that these schemes are competitive with other commonly employed schemes whose security is less well-established. 1 Introduction Message Authentication. Message authentication schemes are an important security tool. As more and more data is being transmitted over networks, the need for secure, high-speed, software-based message authentication is becoming more acute. The setting for message authentication is the following. Two parties A and B agree on a secre...

We describe a software-efficient encryption algorithm named SEAL 3.0. Computational cost on a modern 32-bit processor is about 4 clock cycles per byte of text. The cipher is a pseudorandom function family: under control of a key (first pre-processed into an internal table) it stretches a 32-bit position index into a long, pseudorandom string. This string

We introduce a new technique for constructing a family of universal hash functions.

March, 1997 Abstract We describe a construction of almost universal hash functions suitable for very fast software implementation and applicable to the hashing of variable size data and fast cryptographic message authentication. Our construction uses fast single precision arithmetic which is increasingly supported by modern processors due to the growing needs for fast arithmetic posed by multimedia applications. We report on hand-optimized assembly implementations on a 150 MHz PowerPC 604 and a 150 MHz Pentium-Pro, which achieve hashing speeds of 350 to 820 Mbit/sec, depending on the desired level of security (or collision probability), and a rate of more than 1 Gbit/sec on a 200 MHz Pentium-Pro. This represents a significant speed-up over current software implementations of universal hashing and other message authentication techniques (e.g., MD5-based). Moreover, our construction is specifically designed to take advantage of emerging microprocessor technologies (such as Intel's MMX, ...

Abstract Radio Frequency Identification (RFID) systems are a common and useful tool in manufac-turing, supply chain management and retail inventory control. Optical barcodes, another

This paper introduces two new ideas in the construction of fast universal hash functions geared towards the task of message authentication.

MMX is a new technology to accelerate multimedia applications on Pentium processors. We report an implementation of IDEA on a Pentium MMX that is $1.65$ times faster than any previously known implementation on the Pentium. By parallelizing four IDEA's we reach an unprecedented $78$ Mbits/s throughput per output block on a 166MHz MMX. In the light of rapidly increasing popularity of multimedia applications, causing more dedicated hardware to be built, and observing that most of the current block ciphers do not benefit from MMX, we raise the problem of designing block ciphers (and encryption modes) fully utilizing the basic operations of multimedia.

We present a cryptographic module that can be used both as a cryptographic hash function and as a stream cipher. High performance is achieved through a combination of low work-factor and a high degree of parallelism. Throughputs of 5.1 bits/cycle for the hashing mode and 4.7 bits/cycle for the stream cipher mode are demonstrated on a commercially available VLIW micro-processor.

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