How can block ciphers and stream ciphers share their keys, and why should they be distinct?

Explain what the following lines of code do pad = len(byteblock)%16 * (-1)byteblock_trimmed = byteblock[64:pad]ciphertext = cipher.encrypt(byteblock_trimmed)ciphertext = byteblock[0:64] + ciphertext + byteblock[pad:]

(c) The following table provides all possible block pairs of plaintext/ciphertext when using some block cipher E with a particular key K. Plaintext Ciphertext Plaintext 0000 1100 1000 1111 1001 0111 1010 1110 1011 1001 0010 1101 0001 0010 0011 0100 0101 0110 0111 1011 1100 1101 1110 1111 Ciphertext 0001 0000 0101 0100 0011 1000 0110 1010 Given that a plaintext P was encrypted using this block cipher operating in a counter mode starting with the counter value of 0, i.e. 0, 1, 2, ..., decrypt the ciphertext C = 010001110111.

1. Basics: Each answer should consist of at most three sentences. (a) What does Kerckhoff’s principle say and why is it important? Give an example where Kerckhoff’s principle is violated. (b) Explain the advantages and disadvantages of a One-Time Pad. What is the connection between OTP and Stream Ciphers? (c) State if the following finite fields exist or not and why: GF(10) GF(16) GF(27) GF(66) GF(512)

Please identify the type (a public-key hash or a script hash) of a bitcoin address if (1) the first character of the Base58-encoded Bitcoin address is ‘1’, or (2) the first character of the Base58-encoded Bitcoin address is ‘3’

Explain Thwarting Output-Guessing Attacks in Logic Encryption.

Decrypt Encryption and decryption are mathematical inverses using the Caesar/Rail Fence Cipher Hint: This a split key - one part of the key is used for the Caesar and the other part of the key is used for the Rail Fence. The full key (Caesar and Rail Fence], in hexidecimal, is: 0x7F.