In this paper, we analyze the security of HMAC and NMAC, both of which are hash-based message authentication codes. We present distinguishing, forgery, and partial key recovery attacks on HMAC and NMAC using collisions of MD4, MD5, SHA-0, and reduced SHA-1. Our results demonstrate that the strength of a cryptographic scheme can be greatly weakened by the insecurity of the underlying hash function.

The Microsoft Windows 2000 implementation of Kerberos introduces a new encryption type based on the RC4 encryption algorithm and using an MD5 HMAC for checksum. This is offered as an alternative to using the existing DES-based encryption types. The RC4-HMAC encryption types are used to ease upgrade of existing Windows NT environments, provide strong cryptography (128-bit key lengths), and provi...

The first distinguishing, forgery and second preimage attacks on step-reduced HMAC-SHA-1 have recently been presented by Kim et al. In this note we report on ongoing work to improve their data complexity and present new attacks on HMAC-SHA-1 covering more steps. Additionally, we show how a collision-based technique can be used to reduce the key entropy of NMAC-SHA-1. Finally we comment on the a...

In this article, we study the security of iterative hash-based MACs, such as HMAC or NMAC, with regards to universal forgery attacks. Leveraging recent advances in the analysis of functional graphs built from the iteration of HMAC or NMAC, we exhibit the very first generic universal forgery attack against hash-based MACs. In particular, our work implies that the universal forgery resistance of ...

Taking into consideration the rapid evolution of communication standards that include message authentication and integrity verification, it is realized that constructions like MAC and HMAC, are widely used in the most popular cryptographic schemes since provision of a way to check the integrity of information transmitted over or stored in an unreliable medium is a prime necessity in the world o...

MAC algorithms can provide cryptographically secure authentication services. One of the most popular algorithms in commercial applications is HMAC based on the hash functions MD5 or SHA-1. In the light of new collision search methods for members of the MD4 family including SHA-1, the security of HMAC based on these hash functions is reconsidered. We present a new method to recover both the inne...

Denial-of-service (DoS) attack exploits inherent limitation of resources in wireless networks in attempt to overwhelm and exhaust their finite capacity. In wireless networks, clear-text form of control packets (CP) exhibits a security flaw that can be exploited by attackers to render the networks incapable of providing normal services. While these attacks are quite damaging in terms of consumin...

In this paper we study the security of hash-based MAC algorithms (such as HMAC and NMAC) above the birthday bound. Up to the birthday bound, HMAC and NMAC are proven to be secure under reasonable assumptions on the hash function. On the other hand, if an n-bit MAC is built from a hash function with a l-bit state (l ≥ n), there is a well-known existential forgery attack with complexity 2. Howeve...

The Use of HMAC-SHA-1-96 within ESP and AH Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited...

Internet of Things adalah sistem kompleks yang banyak digunakan dalam cara untuk memajukan kehidupan manusia. Akibatnya, (IoT) memiliki kerentanan keamanan dan memerlukan autentikasi melindungi data pengguna. Memilih jenis sesuai dengan kebutuhan Anda sangat penting mencapai kinerja baik pada perangkat spesifikasi relatif minimal. Karena situasi ini, algoritma Elliptic Curve Cryptography (ECC) ...