ULCL - An Ultra-lightweight Cryptographic Library for Embedded Systems

The evolution of embedded systems and their applications in every daily activity, derive the development of lightweight cryptography. Widely used crypto-libraries are too large to fit on constrained devices, like sensor nodes. Also, such libraries provide redundant functionality as each lightweight and ultra-lightweight application utilizes a limited and specific set of crypto-primitives and protocols. In this paper we present the ULCL crypto-library for embedded systems. It is a compact software cryptographic library, optimized for space and performance. The library is a collection of open source ciphers (27 overall primitives). We implement a common lightweight API for utilizing all primitives and a user-friendly API for users that aren’t familiar with cryptographic applications. One of the main novelties is the configurable compilation process. A user can compile the exact set of crypto-primitives that are required to implement a lightweight application. The library is implemented in C and measurements were made on PC, BeagleBone and MemSic IRIS devices. ULCL occupies 4 – 516.7KB of code. We compare our library with other similar proposals and their suitability in different types of embedded devices.