A matter of shy osprey. RSA Algorithm
In 1976, Whitfield Diffie and Martin Hellman published their article, New Trends in Cryptography, with revolutionary ideas for public-key encryption. And then, three scientists Ronald Ryvest , Adi Shamir and Leonard Adleman in August 1977 published an article in the journal Scientific American , where they described in detail their algorithm using calculations in the ring of integers. As many people know, the idea of the algorithm is the existence of a conditionally one-sided function - ordinary multiplication by a set of prime numbers of large length
(f: P x P -> P * P ), which is computationally difficult to reverse. In other words, knowing n = p * q (where p and q are primes), finding p and q (or factoring the number n) for large n seems to be a demanding task.
In the same issue, a well-known mathematician and scientist Martin Gardner, by agreement of the authors of the algorithm, published a mathematical problem called RSA-129. In it, he wrote a pair of numbers (n, e) - a public key, where the length of the number n was 129 decimal places, and e was equal to 1007, and the encrypted message itself. He promised the decryptor of the message a reward of $ 100, which he put into the bank at 2% per annum. According to analysts, decomposing such a huge number into factors with the existing factorization algorithms and the power of those computers would require 20,000 years of continuous operation (Ron Rivest assumed 40 quadrillennes for a number of 125 characters). But the situation changed ...

Then, in 1994, the young cryptographer of the American army Arjen Lenstra developed an improvement of the Quadratic Sieve algorithm , which allows finding reasonable factors of up to 130 digits in a reasonable time. The asymptotic behavior of the algorithm was O (esqrt (log n * log log n) ), where e is the base of the natural logarithm. By the way, the asymptotics of the trivial factorization algorithm
The answer turned out to be:
RSA-129 = 3490529510847650949147849619903898133417764638493387843990820577
× 32769132993266709549961988190834461413177642967992942539798288533
The lengths of the numbers p and q turned out to be 64 and 65 characters, respectively. The phrase encrypted by Martin Gardner was: " The Magic Words are Squeamish Ossifrage ", which translates as " Magic words are Shy Osprey ", or, according to the Russian Wikipedia, " Magic words are squeamish lamb ." After that, the recommended key length was increased to 140 characters until after 4 years the check number of 140 digits was laid out. In 1998, Bill Gates announced that he provided unlimited funding and computing resources to his company to decompose a number of 200 characters. At the moment, this goal has already been achieved in 2005, the RSA-200 task. Of the $ 100, it’s not difficult to calculate, the interest for 17 years turned out to be approximately $ 140, which were transferred to the free software fund :-)
This whole story was an excellent PR move for the authors of the algorithm and the founders of the company that patented RSA, and received in The result is a $ 900 million profit.
That's what it means to make money wisely;)
Source: Professor Saliy Vyacheslav Nikolaevich, SSU.
I apologize in advance for inaccuracies.
Thank you all for the corrections in the comments!