US Patent 11411728 Proof-of-work key wrapping with individual key fragments

The technology disclosed herein provides a proof-of-work key wrapping system that uses key fragments to cryptographically control access to data. An example method may include: encrypting a first cryptographic key to produce a wrapped key, wherein the first cryptographic key enables a computing device to access content; splitting a second cryptographic key into a plurality of key fragments, wherein the second cryptographic key is for decrypting the wrapped key; selecting a set of cryptographic attributes for deriving at least one of the plurality of key fragments, wherein the set of cryptographic attributes are selected in view of a characteristic of the computing device; and providing the wrapped key and the set of cryptographic attributes to the computing device, the set of cryptographic attributes facilitating determination of the second cryptographic key.