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This paper will introduce simple modifications to the database of the widely deployed Kerberos authentication protocol. The principle's long-term secret key will be independent of the user password with the aim to overcome the weak passwords chosen by the network principal that are susceptible to password guessing attacks, the main drawback of the Kerberos protocol. Instead, the Kerberos Distribution Center will save a profile for every instance in the realm that it mange and the secret key will be generated based on that profile. This profile will be hashed and then, the output digest will be encrypted to generate the secret key. Besides, the lifetime of the secret key will be controlled using the system lifetime. We will use Triple-Des as an encryption algorithm, SHA-256 as a hashing algorithm, and Blum Blum Shub as a random number generator algorithm.

Telemetry is an essential subsystem in Low Earth Orbit (LEO) Remote-Sensing satellites, as it is responsible for gathering satellite housekeeping data from all satellite subsystems, malfunction detection, performance evaluation and statistics. In this paper, a novel Checkout-and-Testing-Equipment (CTE) is proposed which simulates the Telemetry interfaces to other satellite subsystems and the Telemetry inputs such as: satellite sensors, and tests the full functionality of the Telemetry software/hardware. Besides, this work models the Telemetry data-acquisition core (Sensors Commutators) using LabVIEW. This new CTE is designed and implemented using LabVIEW and verified using National Instruments (NI) modules such as: NI Virtual Instrument Software Architecture (VISA), NI PXI-6509, NI PXI-6723 and NI PXI-4110. The Telemetry software framework is developed using the Integrated Development Environment (IDE) of C8051f120 Silicon Labs microcontroller.

Despite the harshness of the space radiation on satellite electronic components, some Commercial Of The Shelf (COTS) can sustain such harsh environment. Thus, the low-cost advantage of the COTS can be utilized given that these electronic components meet the technical design requirements of the targeted satellite subsystem. Because of the complexity of microcontrollers and their various integrated functionality, they present a hardness assurance challenge. A careful technique was followed in analyzing the space radiation effects. Then rigorous tests should be conducted to test the performance of the candidate microcontrollers under these effects. This paper presents the predicted dose depth curve and the total ionizing does test results for a commercial ARM microcontroller for Low Earth Orbit (LEO) satellites. Such test results help estimate the effect of space environment on the microcontroller and decide if such microcontroller is an accepted candidate for LEO missions or not.

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