Ethical Hacking Essentials Practice Test

Which spread spectrum technique uses a pseudo-random noise-spreading code to protect signals from interference?

1. Frequency Hopping Spread Spectrum (FHSS)

2. Direct-Sequence Spread Spectrum (DSSS)

3. Time Hopping Spread Spectrum (THSS)

4. Orthogonal Frequency Division Multiplexing (OFDM)

The correct answer is: Direct-Sequence Spread Spectrum (DSSS)

The choice of Direct-Sequence Spread Spectrum (DSSS) as the correct answer is based on its method of utilizing a pseudo-random noise spreading code to enhance signal protection. In DSSS, the original data signal is modulated with a spreading code that is much wider in bandwidth than the data signal itself. This code is generated using pseudo-random sequences, which helps to spread the signal over a larger frequency band. This technique not only aids in reducing the likelihood of interference from other signals, but it also allows for better resistance against jamming and unauthorized interception. Because the transmitted signal resembles noise, it becomes challenging for unintended receivers to decipher it without knowing the specific spreading code being used. Other options represent different techniques that achieve spread spectrum communication in unique ways. Frequency Hopping Spread Spectrum (FHSS) uses rapid changes in frequency during transmission to avoid interference but does not utilize a pseudo-random sequence for signal modulation in the same manner as DSSS. Time Hopping Spread Spectrum (THSS) involves varying the time slots for transmission but lacks the bandwidth spreading characteristics of DSSS. Orthogonal Frequency Division Multiplexing (OFDM) employs a different modulation scheme focused on efficiently using available bandwidth rather than spreading the signal over a wide range