Diseño e implementación de un algoritmo de cifrado híbrido para sistemas de comunicación crítica

Abstract

In this paper, the development of the degree work is evidenced, which consists of the execution of a hybrid encryption algorithm for mission-critical communication systems through software-defined radio. The algorithm is developed using the Python programming language which allows for RSA asymmetric authentication. The RSA key (public and private) is sent encrypted by a password from the receiver to the transmitter, the transmitter unlocks the public key with which the AES session key is encrypted by RSA, which encrypts the plain text, then it is encrypts the plaintext using the AES (symmetric encryption) algorithm. At the receiver, the session key is decrypted using the RSA private key, which in turn is used to decrypt the plaintext. For this work, samples are taken with image files (.jpg or .png) that have a size between 44.4 kB and 226 kB, which are opened automatically when they arrive. The communication is executed through the GNU Radio software in which an ASK modulation technique is used at a symbol rate of 195.312 kbps, at the time of making this communication it is executed by the USRP-N210 device, a device implemented for the development of Defined Radio by Software, since it allows delegating the hardware functions to the code used by the GNU Radio tool through Python and C++. Throughput, delay, and jitter performance measurements are performed, evaluating the performance of the algorithm, which is why these data are affected only with the adjusted bit rate in the GNU Radio block diagrams. The throughput varies with very slight values since it is conditioned to the packaging and the control information that the UDP protocol consumes through the communication between the computer and the USRP-N210 for its operation.