A system and method for generating an m-dimensional signature vector in a computing device is provided. The signature vector may be generated from a plurality of key-value pairs, each comprising a unique identifier and an associated non-zero value. Each element of the m-dimensional signature vector is calculated based on a summation of a plurality of terms. Each of the terms is calculated from a respective key-value pair by generating a seed based on the key of the respective key-value pair and an element identifier associated with the vector element being calculated; generating a pseudo-random number from the generated seed; and multiplying the pseudo-random number by the value of the respective key-value pair, wherein m