answers: additive
context: bits in the decrypted plaintext by manipulating the ciphertext. This is called malleability. Example using the Python programming language. XOR cipher In cryptography, the simple XOR cipher is a type of "additive cipher", an encryption algorithm that operates according to the principles: where formula_1 denotes the exclusive disjunction (XOR) operation. This operation is sometimes called modulus 2 addition (or subtraction, which is identical). With this logic, a string of text can be encrypted by applying the bitwise XOR operator to every character using a given key. To decrypt the output, merely reapplying the XOR function with the key will remove </s> XTR In cryptography, XTR is an algorithm for public-key encryption. XTR stands for 'ECSTR', which is an abbreviation for Efficient and Compact Subgroup Trace Representation. It is a method to represent elements of a subgroup of a multiplicative group of a finite field. To do so, it uses the trace over formula_1 to represent elements of a subgroup of formula_2. From a security point of view, XTR relies on the difficulty of solving Discrete Logarithm related problems in the full multiplicative group of a finite field. Unlike many cryptographic protocols that are based on the generator of the full multiplicative </s> S and S — S operates on the left 4-bit nibble and S operates on the right. The resultant outputs are concatenated and then combined with the subkey using exclusive or (XOR); this is termed ""key interruption"". This is followed by a permutation operation in two stages; the first permutes each byte under a fixed permutation. The second stage mixes bits between the bytes. The key-scheduling algorithm is relatively simple. Initially, the 128 key bits are loaded into a shift register. Each round, the left 64 bits of the register form the subkey, and right eight bits form the ICB
question: the xor process is used in which cipher