Encrypted Keyword Search via Ciphertext Reordering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cloud storage services, encrypting data ensures security, but it renders existing search processes impossible, limiting the ability to access encrypted files without the secret key.
Innovation Solution
An apparatus and method for encryption and search considering binary search, which generates and reorders keyword and address ciphertexts, allowing for secure search operations even with dynamic databases and arbitrary keyword lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data is encrypted to ensure security in cloud storage, then data confidentiality is improved, but search capability deteriorates
Solution Approach 1:
The patent segments the encryption system into multiple components: symmetric encryption for data confidentiality, asymmetric encryption for key management, and separate index structures for searchability. The ciphertext is divided into data portions and keyword portions, allowing independent optimization of security and search functions without compromising either.
Solution Approach 2:
The patent introduces cryptographic intermediaries including public-private key pairs and encrypted index structures that mediate between the encrypted data and search operations. These intermediaries enable the cloud server to perform search operations on encrypted data without accessing the plaintext, thus maintaining confidentiality while enabling search functionality.
2Productivity
If existing search processes are used on encrypted data, then search speed is improved, but data security deteriorates
Solution Approach 1:
The patent performs preliminary encryption of keywords and creation of encrypted index structures before the actual search operation. The cloud server receives pre-processed encrypted indexes that enable direct search operations on ciphertext without requiring decryption, thus maintaining both security and search efficiency.
Solution Approach 2:
The patent applies partial decryption or verification only to specific portions of data (keywords or indexes) rather than the entire dataset. This allows the system to verify search terms or indexes without exposing the full encrypted database, maintaining security while enabling efficient search operations.
3Reliability
If the cloud server stores encrypted data without the secret key, then data security is improved, but search functionality deteriorates
Solution Approach 1:
The patent creates a multi-functional system where the cloud server can simultaneously store encrypted data, maintain encrypted indexes, and perform search operations without possessing the decryption key. The system achieves multiple functions (security, storage, search) through a unified cryptographic framework that works with encrypted data throughout.
Solution Approach 2:
The patent transitions the search problem from the plaintext domain to the ciphertext domain by creating encrypted index structures. Instead of searching in one dimension (plaintext), the system operates in another dimension (ciphertext space) where search operations can be performed on encrypted data using cryptographic protocols.
Data Source
AI summary
The present disclosure relates to a sensor network, machine type communication (MTC), machine-to-machine (M2M) communication, and technology for internet of things (IoT). The present disclosure may be applied to intelligent services based on the above technologies, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method for performing an encryption process is provided. The method includes generating a plurality of keys used for keyword encryption and file encryption, generating an address ciphertext by performing a first encryption process on each of addresses that a plurality of files are stored, generating a keyword ciphertext by performing a second encryption process on each of a plurality of keywords that are included in each of the plurality of files, reordering the address ciphertext and the keyword ciphertext based on the keyword ciphertext, and storing the reordered address ciphertext and keyword ciphertext.