□ CTR(CounTeR) mode
○ CTR Encryption : XOR(En(CTR[i]), P[i])
- Encryption(Current counter(CTR[i])) → XOR(Encryption result, Current plaintext block(P[i])) → Current ciphertext block(C[i])
○ CTR Decryption : XOR(En(CTR[i]), C[i])
- Encryption(Current counter(CTR[i])) → XOR(Encryption result, Current ciphertext block(C[i])) → Current plaintext block(P[i])
P.S. Symbol information
- En:Encryption / De:Decryption
- C:Cipher text / P:Plain text
- i:Each step(Ex. Current step:i / one Previous step:i-1 / one Next step:i+1)
- C:Cipher text / P:Plain text
- i:Each step(Ex. Current step:i / one Previous step:i-1 / one Next step:i+1)