2.1. Data Encryption phase
USEA encrypts 512-bit blocks of plaintext to cipher text by a 256-bit main key that from now we call it MK. In default, USEA consists of 20 identical rounds, but we can increase or decrease the rounds for amplification of our algorithm in specific hardware or software implementation. Note that Decreasing rounds of algorithm reduces its security against attacks. USEA uses different algebratic, logic and arithmetic operations for data encryption and decryption.
We use the following three mathematical operations in USEA:
1. Bitwise XOR
2. Addition modulo 232
3. Multiplication modulo 232+1
For every round, the 512-bit input is split into two 256-bit sub blocks: T1 and T2.
All rounds of algorithm,