The Design And Implement Of A Hybrid Encryption Scheme Based On AES And ECDSA

With the rapid development of network technology, the demand to protect digitalcontent is growing. Cryptography is the core of information security technology; it canensure data confidentiality, integrity, non-repudiation, etc. Two typical cryptographysystems are symmetric-key cryptography and public-key cryptography. Symmetric-keycryptography has simple algorithm and fast encryption speed, so it’s often used to encryptlarge amounts of data. But its security depends on its key, so the key management and keyexchange is difficult. The most outstanding representation algorithm is AES (AdvancedEncryption Standard). Public-key cryptography’s key distribution is more convenient, andit’s more suitable to the computer network environment, but the drawback is the complexalgorithm and slow encryption speed. Nowadays, ECC (Elliptic Curve Cryptosystems) iswidely considered to be the best public-key cryptography for a given key length.Symmetric-key cryptography and Public-key cryptography each has its advantageand disadvantage, thus consider combine them to obtain the hybrid cryptographic scheme.File processing module is designed to processing files of different types, such as Excel,Html, PDF, Rtf, Txt, Word, etc. AES is chosen to be the base symmetric-key algorithm,and MEAA (Multithreading Encryption Algorithm based on AES) is implemented to meetthe demand of processing large files. Digital Signature is easy to be implemented based onPublic-key cryptography, after a preliminary study on the mathematical theory of ECC, weconducted a ECDSA (Elliptic Curve Digital Signature Algorithm) and proposed the hybridcryptographic scheme SME (Scheme combines of MEAA and ECDSA).The experiment compared MEAA’s encryption time on the file whose size are1KB,1MB,10MB respectively when the thread number ranges from1to10, the result showswhen thread number is4the processing time comes to the minimum. Then compares theMEAA and AES’s processing time on files of different sizes when the thread number is4,the result shows MEAA has a good performance. ECDSA’s signature and verification istest also. So we get a hybrid cryptographic scheme SME which has good performance.