(a)(i) Define the term encryption. (ii) Tick two authentication techniques involved in security measure from Table 1. Table 1 TECHNIQUE TICK() Firewall Biom...

(a)(i) Encryption is the process of converting readable data (plaintext) into a coded, unreadable form (ciphertext) using an algorithm and a key, so that only an authorised person holding the correct key can decode (decrypt) and read it. Its purpose is to protect the confidentiality of data during storage or transmission.

(a)(ii) Authentication techniques (tick two): Of the four items listed, only Biometric and Password are used to verify a user's identity. A firewall is a network-protection barrier and an intranet is a private network; neither authenticates a user.

(a)(iii) Two features of data encryption:

• It uses a key together with an algorithm to scramble the data, and the same or a matching key is required to reverse it.
• The encrypted output (ciphertext) is unintelligible to anyone who intercepts it without the key, so it preserves confidentiality and integrity of the message.

(b) Four factors that may cause delay in transferring data between mobile phones:

1. Weak or unstable network / signal strength between the two devices (poor Bluetooth or Wi-Fi connection).
2. Large file size of the data being exchanged, which takes longer to send.
3. Low available bandwidth or transfer speed of the connection technology being used.
4. Distance or obstacles between the phones, or interference from other electronic/radio devices.

(Other acceptable factors: low battery power forcing power-saving mode, a slow or busy processor, or too many applications running in the background.)