The problem as computer science states it
Diffie and Hellman's 1976 result, recognized with the 2015 Turing Award, solved a problem that had been assumed insoluble: how two parties who have never met and share no secret can establish confidential communication over an open channel. Public-key cryptography made the modern internet possible, and it solved authentication and confidentiality between endpoints.
It did not solve authorization across organizational boundaries, and the gap is the one that has constrained everything since. Public-key infrastructure establishes who a party is. It does not establish what that party may do with a resource governed by someone else, under terms set by a third party, in a jurisdiction belonging to a fourth. Every deployment therefore requires a bilateral agreement negotiated per counterparty, which is why cross-organizational data use remains rare despite the cryptography being settled for fifty years.
Why the substrate made it unsolvable
Authorization requires a shared frame of reference for what permissions mean, and no such frame existed that did not require the parties to agree on one. Every attempt produced either a central authority that all parties had to trust — reintroducing the problem public-key cryptography had removed — or a federation agreement negotiated pairwise, which does not scale.
What the paradigm supplies
The Unified Trust Model supplies coherence without agreement, which is the property imported from Riemannian geometry: local regions carry independent internal structure, and coherence across the manifold is achieved by requiring transition functions to compose consistently rather than by requiring the local geometries to agree. Applied to authorization, incompatible trust regimes coexist over the same resource with no central authority reconciling them and none required to withdraw. EasyAccess is the authorization layer that operates on that substrate, enabling person-centered cross-organizational authorization without accounts, migrations or bilateral integration.
The relation to the 1976 result is completion rather than replacement. Public-key cryptography solved identity between parties; this solves permission among them. The two compose, and the second was unreachable before the first existed.
A demonstration that the primitive does not provide the properties claimed, or that prior work already provides them.
Diffie-Hellman 1976