A symmetric key is a cryptographic system thatQuestion 1Answera.Uses two keysb.Uses one keyc.Uses three keysd.Uses four keys

Understanding Symmetric Key Cryptography

In symmetric key cryptography, the fundamental concept is that the same key is used for both the encryption and decryption processes. This means both the sender and receiver must have access to the same secret key to convert plaintext into ciphertext and vice versa.

Analysis of Options

1. Option a: Uses two keys - This describes asymmetric or public-key cryptography, where two keys (public and private) are employed.
2. Option b: Uses one key - This correctly defines symmetric key cryptography, where only one key is necessary for both operations.
3. Option c: Uses three keys - This is not correct in the context of any standard cryptographic system.
4. Option d: Uses four keys - This option is also incorrect for standard definitions in cryptography.

Conclusion

The correct answer is: b. Uses one key.

This represents the defining characteristic of symmetric key cryptography effectively.