1. A method comprising: performing modular exponentiation in a cryptographic computation such that memory accesses are independent of the numerical value of the exponent, wherein said performing modular exponentiation is to comprise replacing a conditional multiplication operation with an unconditional multiplication operation and the unconditional multiplication operation is to be based on an obscuring factor; and determining the obscuring factor for each bit of the exponent by adding one to a result of multiplying a quantity by a selected bit of the exponent, the quantity comprising a message minus one.