Security features such as privacy and device authentication are required in wireless sensor networks, electronic IDs, Radio Frequency Identification tags, and many other applications. These features are provided using cryptography. Symmetric key cryptography, where the key is distributed between the communication parties prior to communication, does not provide adequate solution for large scalable systems such as sensor networks. In these cases, public-key cryptography should be used. However, public-key algorithms are typically more computationally intensive than their symmetric key counterparts, which creates difficulties in meeting the strict area, power, and energy requirements. Elliptic curve cryptography, because of relatively small operand sizes, can be used to answer the imposed challenges. In this paper, we present a processor for elliptic curve cryptography over GF(2(163)). This processor can perform elliptic curve point multiplication as well as general modular operations. The processor is flexible enough to support multiple cryptographic protocols. The chip is fabricated using UMC .13 m 1P8M process, resulting in a core area of 0.54 mm(2). The energy consumption to perform one elliptic curve point multiplication is 5.1J. The design features lightweight countermeasures against side-channel attacks. A security evaluation shows the effectiveness of such countermeasures. Copyright (c) 2016 John Wiley & Sons, Ltd.