LTE Security potential vulnerability and algorithm enhancements

In this paper we investigate potential vulnerabilities in the implementation of encryption processes within the EEA2 algorithm of Long-Term Evolution (LTE), and we propose an enhancement for the security features in LTE. We show that during the encryption process in EEA2, a leakage of 128 bits of plain text and its corresponding cipher text in a PDU, could potentially allow an intruder to recover the key, hence the entire original plain text could be compromised. We propose a solution by adding a matrix block to the encryption process of the cipher text. The proposed encryption process uses a random set of numbers in the form of a matrix, which is used with the cipher text in order to obtain an enriched block of ciphered data. We have implemented the algorithm in Matlab, and successfully tested several use cases to produce an enriched block of encrypted data, which is then decrypted to obtain the original text. We also show by simulation that enriching the data using this system will improve the encryption process; however, the cost is increasing the complexity of the algorithm.