The characteristics of the wireless network determinethe requirement of lightweight cryptography. Towards the hugecost of an existing algorithm such as MD5, this paper proposes amessage digest scheme based on the RC4 algorithm which broadens the application area of the RC4 and decreases the requirementof resource or cost. To test the randomicity of the algorithm's digest, fifteen kinds of randomicity test to NIST randomicity teststandard had been done, and the comparative analysis whichcompares the digest's randomicity of the algorithm with MD5 hadbeen performed as well. The performance of the algorithm hadbeen analyzed in aspects of mono-directivity, randomicity, practicality and complexness. Statistic tests and analysis results illustrated that our scheme was of low cost of computing, good statisticperformance, high running speed and lightweight.
