To provide a high-security guaran- tee to network coding and lower the comput- ing complexity induced by signature scheme, we take full advantage of homomorphic prop- erty to build lattice signature schemes and sec- u...To provide a high-security guaran- tee to network coding and lower the comput- ing complexity induced by signature scheme, we take full advantage of homomorphic prop- erty to build lattice signature schemes and sec- ure network coding algorithms. Firstly, by means of the distance between the message and its sig- nature in a lattice, we propose a Distance-bas- ed Secure Network Coding （DSNC） algorithm and stipulate its security to a new hard problem Fixed Length Vector Problem （FLVP）, which is harder than Shortest Vector Problem （SVP） on lattices. Secondly, considering the bound- ary on the distance between the message and its signature, we further propose an efficient Bo- undary-based Secure Network Coding （BSNC） algorithm to reduce the computing complexity induced by square calculation in DSNC. Sim- ulation results and security analysis show that the proposed signature schemes have stronger unforgeability due to the natural property of lattices than traditional Rivest-Shamir-Adleman （RSA）-based signature scheme. DSNC algo- rithm is more secure and BSNC algorithm greatly reduces the time cost on computation.展开更多
The straight-line method in computing for depreciation expense is the prevailing method used in the Philippines. This paper aims to determine the rationale behind the use of this method. The objective of the study is ...The straight-line method in computing for depreciation expense is the prevailing method used in the Philippines. This paper aims to determine the rationale behind the use of this method. The objective of the study is to determine the length of time within which the depreciation method is used, reasons in using the method, the rate of depreciation used by the companies, and the effects of the depreciation expense on their operating expenses. It also determines if the companies＇ decisions to use the straight-line method are influenced by the factors mentioned by Reynolds （196 I）----expected amount of services over the life of assets, the amount and timing of operating costs, the decline in the physical efficiency of the assets, and the rate of return--and if they considered capital investments and tax reduction in using this method. The study shows that companies and educational institutions use the straight-line method of computing depreciation expenses, because it is easy to use in computing the depreciation expenses, in comparing with previous years＇ computations, and in keeping track of the expenses. It is also convenient for tax administration and financial reporting. The rate of depreciation used varies, because the companies and educational institutions use their past experiences in determining the life of fixed assets. The percentage of depreciation to the operating expenses also varies. The companies and educational institutions adhered to the factors mentioned by Reynolds （1961） in choosing the straight-line method of depreciation. The companies did not consider reduction of tax in using the straight-line method.展开更多
基金ACKNOWLEDGEMENT This work was partially supported by the National Basic Research Program of China under Grant No. 2012CB315905 the National Natural Sci- ence Foundation of China under Grants No. 61272501, No. 61173154, No. 61370190 and the Beijing Natural Science Foundation under Grant No. 4132056.
文摘To provide a high-security guaran- tee to network coding and lower the comput- ing complexity induced by signature scheme, we take full advantage of homomorphic prop- erty to build lattice signature schemes and sec- ure network coding algorithms. Firstly, by means of the distance between the message and its sig- nature in a lattice, we propose a Distance-bas- ed Secure Network Coding （DSNC） algorithm and stipulate its security to a new hard problem Fixed Length Vector Problem （FLVP）, which is harder than Shortest Vector Problem （SVP） on lattices. Secondly, considering the bound- ary on the distance between the message and its signature, we further propose an efficient Bo- undary-based Secure Network Coding （BSNC） algorithm to reduce the computing complexity induced by square calculation in DSNC. Sim- ulation results and security analysis show that the proposed signature schemes have stronger unforgeability due to the natural property of lattices than traditional Rivest-Shamir-Adleman （RSA）-based signature scheme. DSNC algo- rithm is more secure and BSNC algorithm greatly reduces the time cost on computation.
文摘The straight-line method in computing for depreciation expense is the prevailing method used in the Philippines. This paper aims to determine the rationale behind the use of this method. The objective of the study is to determine the length of time within which the depreciation method is used, reasons in using the method, the rate of depreciation used by the companies, and the effects of the depreciation expense on their operating expenses. It also determines if the companies＇ decisions to use the straight-line method are influenced by the factors mentioned by Reynolds （196 I）----expected amount of services over the life of assets, the amount and timing of operating costs, the decline in the physical efficiency of the assets, and the rate of return--and if they considered capital investments and tax reduction in using this method. The study shows that companies and educational institutions use the straight-line method of computing depreciation expenses, because it is easy to use in computing the depreciation expenses, in comparing with previous years＇ computations, and in keeping track of the expenses. It is also convenient for tax administration and financial reporting. The rate of depreciation used varies, because the companies and educational institutions use their past experiences in determining the life of fixed assets. The percentage of depreciation to the operating expenses also varies. The companies and educational institutions adhered to the factors mentioned by Reynolds （1961） in choosing the straight-line method of depreciation. The companies did not consider reduction of tax in using the straight-line method.
