please answer the questions even the one for class if you know nay part of it

a)Qne Time Pad (OTP) encryption is highly secure, but why we do not see it much in practice? Explain at least two reasons (some discussed in-class) [3p] b)Why does an ideal OTP encryption achieve information- theoretical security? [2pt] c In the class (on board), we discussed the derivation of ar encryption method, which shares a similar design template to an OTP, but it uses a cryptographic hash function and a private key as a seed (output of a true random number generator) to achieve computationally-secure encryption. Please describe how encryption and decryption work in this simple XOR based encryption/decryption template. You can write a short algorithm as it has been shown in the class (one for encryption and another for decryption). After writing your short algorithm, compare the advantages and disadvantages of this approach with basic OTP, 10pt