A computer-implemented method, comprising: accessing an electronic ledger (110; 218) that identifies a plurality of 3D model files that have been made available for distribution, wherein respective instances of the electronic ledger are separately maintained by each of a plurality of nodes in a computing network; obtaining, by a computing device using information contained in the electronic ledger, a particular 3D model file among the plurality of 3D model files identified in the electronic ledger, wherein the particular 3D model file obtained by the computing device is encrypted based on a secret key; obtaining the secret key at the computing device, wherein the secret key is encrypted based on a public key associated with the computing device; decrypting the secret key using a private key associated with the computing device that corresponds to the public key; after decrypting the secret key, decrypting the particular 3D model file using the secret key; after decrypting the particular 3D model file, executing the particular 3D model file on the computing device to print a physical 3D object; and providing an alert from the computing device to one or more computers associated with a provider of the particular 3D model file based on identifying that at least one of the following conditions has occurred: (i) the computing device has completed executing the particular 3D model file, (ii) the computing device has obtained the secret key for decrypting the particular 3D model file, (iii) the computing device has decrypted the secret key, or (iv) the computing device has decrypted the particular 3D model file. accessing an electronic ledger (110; 218) that identifies a plurality of 3D model files that have been made available for distribution, wherein respective instances of the electronic ledger are separately maintained by each of a plurality of nodes in a computing network; obtaining, by a computing device using information contained in the electronic ledger, a particular 3D model file among the plurality of 3D model files identified in the electronic ledger, wherein the particular 3D model file obtained by the computing device is encrypted based on a secret key; obtaining the secret key at the computing device, wherein the secret key is encrypted based on a public key associated with the computing device; decrypting the secret key using a private key associated with the computing device that corresponds to the public key; after decrypting the secret key, decrypting the particular 3D model file using the secret key; after decrypting the particular 3D model file, executing the particular 3D model file on the computing device to print a physical 3D object; and providing an alert from the computing device to one or more computers associated with a provider of the particular 3D model file based on identifying that at least one of the following conditions has occurred: (i) the computing device has completed executing the particular 3D model file, (ii) the computing device has obtained the secret key for decrypting the particular 3D model file, (iii) the computing device has decrypted the secret key, or (iv) the computing device has decrypted the particular 3D model file. (i) the computing device has completed executing the particular 3D model file, (ii) the computing device has obtained the secret key for decrypting the particular 3D model file, (iii) the computing device has decrypted the secret key, or (iv) the computing device has decrypted the particular 3D model file.