 Just less than five gigabytes of disk storage was required and about 2.5 gigabytes of RAM for the sieving process.The first RSA-512 factorization in 1999 required the equivalent of 8,400 MIPS years, over an elapsed time of about seven months.Rivest, Shamir, and Adleman noted that Miller has shown that – assuming the truth of the Extended Riemann Hypothesis – finding "d" from "n" and "e" is as hard as factoring "n" into "p" and "q" (up to a polynomial time difference).