## 1 Introduction  
The technological cost reduction of network devices has lead to the expansion of personal portable computers and the appearance of new types of networks. Heterogeneous ubiquitous networks formed by small and constrained devices are actively researched or already in use, and security mechanisms have to be provided to protect them from malicious attacks. The main nature of ubiquitous networks (providing easy network interconnections anytime and anywhere) makes the introduction of measures to ensure the correct operation of the protocols is very necessary at all layers; from networking operations (routing and network management) to collaborative enforcing protocols or privacy protecting mechanisms. Therefore, it is important to know the real cost of cryptography in small devices and design client protocols that suit this context.  
Some research works have studied the performance of cryptographic algorithms in small and constrained devices as Personal Digital Assistants (PDAs). However, none of them provides a global view of the impact of cryptographic techniques in the system, nor can be inferred since tests do not share any common ground. Some works focus on a few types of cryptosystems [1, 2, 3, 4], while others only analyze the utilization of some particular resources [5, 6]. Specifically, the work of [PERSON] _et al._[5] is one of the most interesting because it covers symmetric and asymmetric cryptography (including elliptic curve algorithms), and hash algorithms. However, it only deals with energy consumption.  
In this paper we present a study of different cryptographic techniques in embedded devices based on ARM architectures, measuring the computational ability to process cryptographic functions and the battery power consumption. We are interested in a broad vision of the problem, how security affects the autonomy and functioning of a device with the goal to design efficient secure communication protocols. The primary security needs of network protocols are to provide authenticity and integrity. Thus, we center our study on block ciphers (because MACs can be constructed from block ciphers), hash functions, and public key digital signature algorithms.  
We conducted benchmarking tests for the most used algorithms nowadays and the ones recommended by international organizations and projects (NIST, NESSIE, CRYPTREC). The chosen block cipher algorithms are Data Encryption Standard (DES), Triple DES (3 DES) and Advanced Encryption Standard (AES). The tested hash functions are Message Digest 5 (MD5), Secure Hash Algorithm 1 (SHA-1) and Secure Hash Algorithm 2 (SHA-2). In public key cryptography, we have tested Rivest Shamir Adleman (RSA), Digital Signature Algorithm (DSA), Elliptic Curve Digital Signature Algorithm (ECDSA) and emerging algorithms based on pairings (Boneh-Lynn-Shacham (BLS) and Boneh-Boyen (BB)). We have used the procedures of OpenSSL-0.98d C library to program the tests, except for the pairing schemes, in which we have used the PBC_sig-0.0.2 library from Stanford University.  
The rest of the paper is organized as follows. We first describe the testing environment and measurement system. Then, in Section 3, we present the basic costs of the system and the performance of chosen cryptosystems. Finally, in Section 4 we summarize the most relevant results.