US Patent Application 18231626. ENCRYPTION DEVICE, DECRYPTION DEVICE, ENCRYPTION METHOD, DECRYPTION METHOD, AND COMPUTER READABLE MEDIUM simplified abstract
ENCRYPTION DEVICE, DECRYPTION DEVICE, ENCRYPTION METHOD, DECRYPTION METHOD, AND COMPUTER READABLE MEDIUM
Organization Name
Mitsubishi Electric Corporation
Inventor(s)
ENCRYPTION DEVICE, DECRYPTION DEVICE, ENCRYPTION METHOD, DECRYPTION METHOD, AND COMPUTER READABLE MEDIUM - A simplified explanation of the abstract
This abstract first appeared for US patent application 18231626 titled 'ENCRYPTION DEVICE, DECRYPTION DEVICE, ENCRYPTION METHOD, DECRYPTION METHOD, AND COMPUTER READABLE MEDIUM
Simplified Explanation
The patent application describes an encryption device that divides a plaintext into multiple parts and encrypts them using a block cipher.
- The encryption device uses a key and a replacement function to encrypt each part of the plaintext.
- It generates an n-bit value for each part by encrypting the previous value using the key.
- The device also generates a value by combining the encrypted values and the corresponding parts of the plaintext.
- To detect any alteration of the ciphertext, the device generates an authenticator using a value and the last encrypted value.
- The encryption device ensures secure encryption and detection of alterations in the ciphertext.
Original Abstract Submitted
An encryption device divides a plaintext M to generate a value M[1], . . . , and a value M[m]. The encryption device generates an n-bit value B[i] by encrypting a value B[i−1] by a block cipher with a value T[i−1] as a key, for each integer i of i=1, . . . , m in ascending order, generates a value C[i] from the value B[i] and a value M[i], and generates an n-bit value T[i] from a value P(T[i−1]) obtained by converting the value T[i−1] using a replacement function P, a value F(B[i]) obtained by converting the value B[i] using a replacement function F, and the value C[i]. The encryption device generates a ciphertext C by connecting the values C[i] for i=1, . . . , m. The encryption device generates from a value H[m] and the value B[m], an authenticator Tag for detecting an alteration of the ciphertext C.
