The rapid entry in digital transformation and Covid-19 moved many activities to the Internet. The application of cybersecurity tools gives a sense of good security condition of the used digital services. This is often how things look on the surface, but the problems sometimes is hard to notice. The current study presents weaknesses in the still widely used cryptographic algorithm RSA, which allows RSA cryptographic keys to be compromised. It demonstrates the connection with RNG as the root of all the resulting controversies around the issues under consideration.