Technology which is hidden, obscure, or very rare. Theoretically, anything, even macroscale dumbtech, can be classified as cryptotechnology. However, the term is more often applied to transapientech or godtech creations.
Some cryptotechnologies are actually nothing but a memetic ploy (this is sometimes known as rumorware), but others are genuine devices, sometimes rare and one-off, sometimes dangerous, sometimes just inscrutable to lower toposophics. Because of the difficulty of procuring it, even many experts in the field often disagree over what is authentic and what is mere folklore.
The study of cryptotechnology is known as cryptotechology. While most cryptotechologists are higher toposophic minds, it is also possible for a dedicated and highly augmented modosophont to engage in research and make credible contributions to the field.