A computer implemented method of controlling access to a digital asset specifying how an artefact is to be rendered, wherein the method comprises: receiving the digital asset and an indication of a first transaction in a decentralised sequential transactional database ; verifying the digital asset by evaluating a digital hash of the asset to compare with a hash stored in the first transaction and, responsive to the verification, securely storing the digital asset; generating a second transaction in the decentralised sequential transactional database to indicate to prospective renderers the availability of the digital asset for rendering the artefact; receiving a request to access the digital asset by a requesting renderer , the request including an indication of a third transaction in the decentralised sequential transactional database; accessing the third transaction and responsive to a determination that the third transaction indicates that the requesting renderer is authorised to access the digital asset for rendering the artefact, securely communicating the digital asset to the requesting renderer, the method further comprising: receiving one or more criteria each defining criteria for receipt and/or consumption of the digital asset for rendering by a renderer and/or rendering of the artefact determined to meet a predetermined suitability; defining a subset of a plurality of renderers satisfying the one or more criteria based on characteristics of the renderers and the one or more criteria, and wherein the communication of the digital asset to the requesting renderer is further conditional on the requesting renderer belonging to the defined subset of renderers. receiving the digital asset and an indication of a first transaction in a decentralised sequential transactional database ; verifying the digital asset by evaluating a digital hash of the asset to compare with a hash stored in the first transaction and, responsive to the verification, securely storing the digital asset; generating a second transaction in the decentralised sequential transactional database to indicate to prospective renderers the availability of the digital asset for rendering the artefact; receiving a request to access the digital asset by a requesting renderer , the request including an indication of a third transaction in the decentralised sequential transactional database; accessing the third transaction and responsive to a determination that the third transaction indicates that the requesting renderer is authorised to access the digital asset for rendering the artefact, securely communicating the digital asset to the requesting renderer, the method further comprising: receiving one or more criteria each defining criteria for receipt and/or consumption of the digital asset for rendering by a renderer and/or rendering of the artefact determined to meet a predetermined suitability; defining a subset of a plurality of renderers satisfying the one or more criteria based on characteristics of the renderers and the one or more criteria, and wherein the communication of the digital asset to the requesting renderer is further conditional on the requesting renderer belonging to the defined subset of renderers. receiving one or more criteria each defining criteria for receipt and/or consumption of the digital asset for rendering by a renderer and/or rendering of the artefact determined to meet a predetermined suitability; defining a subset of a plurality of renderers satisfying the one or more criteria based on characteristics of the renderers and the one or more criteria, and wherein the communication of the digital asset to the requesting renderer is further conditional on the requesting renderer belonging to the defined subset of renderers. <EOS>