Data encryption and decryption method and apparatus
View Patent ↗This present application relates to data encryption and decryption technology, and especially relates to a data encryption and decryption method and apparatus. The described encryption method comprises: packeting plaintext data to be encrypted, randomly assigning an encryption function an encryption key to each group of the plaintext data, encrypting each group of the plaintext data with the encryption function and key respectively, and arranging the encrypted data according to its corresponding position in the plaintext data to form a ciphertext. The encryption apparatus includes: packet module, encryption function and key random assignment module and encryption processing module. This application also provides a data decryption method and apparatus. This invention randomly assigns an encryption function and encryption key to the plaintext to be encrypted, and uses the assigned encryption function and key to encrypt the plaintext data to arrange and form a ciphertext, greatly strengthening the security of data storage, and achieving the perfect secrecy of data.
1. A data encryption method comprising:
packeting plaintext data to be encrypted;
generating true random numbers with a predetermined length and a random seed with a predetermined length formed by the true random numbers;
establishing an encryption function and key set and assigning an index to each encryption function and each encryption key in the encryption function and key set;
acquiring data from the random seed to generate an encryption function and key index random string;
traversing synchronously the encryption function and key index random string and the plaintext to be encrypted;
assigning an encryption function and an encryption key randomly to each group of the plaintext data;
encrypting each group of the plaintext data with the encryption function and key respectively; and
arranging the encrypted data according to a corresponding position of the data encrypted in the plaintext data to form a ciphertext;
wherein the encryption function and key set comprises the encryption functions and encryption keys of all conversion paths covering from any bit data 0 or 1 in the plaintext to a bit data 0 or 1 at the corresponding position in the ciphertext, and correspondingly, the step of establishing comprises:
selecting an encryption function and an encryption key to cover maximum possible conversion paths from the plaintext to ciphertext;
recording the possible conversion paths;
determining whether all possible conversion paths are completely covered; if so, using all the selected encryption functions and keys to create the encryption function and key set; otherwise, selecting another encryption function covering the maximum possible conversion paths of the remaining;
recording the paths covered by the current encryption function and key;
re-selecting an encryption function and an encryption key covering the maximum possible conversion paths not covered, until the selected encryption function and key can cover all the possible conversion paths; and
using the encryption functions and keys selected to create the encryption function and key set.
2. The method of claim 1 wherein the step of acquiring comprises:
generating a message digest value of the encryption function and key index random string through message digest operation; and
comparing the message digest value with the previously stored message digest values, and if the same, acquiring the data from the random seed again to generate a new encryption function and key index random string, and then comparing the message digest values until a different encryption function and key index random string is determined; if not same, saving the encryption function and key index random string currently generated.
3. The method of claim 1 wherein each group of the plaintext data comprises at least one bit data.