Communication between nodes in a sensor network is often secured by the use of symmetric keys installed on them before deployment. A more efficient method is to install sensors with a small amount of secret information that can be used to generate a pairwise common key when required. We propose new key agreement algorithms based on matrix factorization that requires a maximum of m multiplications to generate a key, where m ≤ N is a system parameter and N is the total number of nodes in the network.