The RSA algorithm works because, when n is sufficiently large, deriving d from a known e and n will be an impractically long calculation — unless we know p, in which case we can use the shortcut.

The RSA algorithm has become an encryption standard for many e-commerce security applications. The patent for it was issued to MIT on Sept. 20, 1983, and licensed exclusively to RSA Security.

A recent research paper makes the claim that the RSA cryptographic algorithm can be broken with a quantum algorithm. Skeptics warn: don’t believe everything you read.

Despite RSA's gesture, several competitors who have paid royalties for use of the algorithm for up to 17 years, argue that the industry could have done with the patent relaxation earlier.

RSA is currently doing an internal review of all of its products to see where the algorithm gets invoked and to change those. A company spokesman said the review is expected to be completed next week.