Topic: Cryptography and Network Security
If an encryption key is n bits long, then how many distinct encryption keys are possible?
- A. $2^{n}$
- B. $2^{n}-1$
- C. $(n\times(n+1))/2$
- D. 2n
Answer: A. $2^{n}$
Explanation: In a binary system, each bit can independently take one of two values (0 or 1). For a key that is $n$ bits long, the total number of distinct possible combinations is $2 \times 2 \times \dots \times 2$ ($n$ times), which equals $2^n$.