Abstract: Key rotation verification without decryption is provided. Two ciphertext inputs encrypted from a plaintext input by an encryption function using different cryptographic keys are input, wherein the encryption function is selected from a function family having an output space of one or more convex sets. A divergence between the two ciphertext inputs is computed. A membership oracle is executed on the two ciphertext inputs, wherein the two ciphertext inputs are determined to be members of the same convex set of the one or more convex sets if the computed divergence satisfies a separation condition. The two ciphertext inputs are validated to both correspond to the same plaintext input, responsive to determining that the two ciphertext inputs are members of the same convex set, wherein the two ciphertext inputs do not correspond to the same plaintext input if the two ciphertext inputs are not members of the same convex set.

Abstract: Key rotation verification without decryption is provided. Two ciphertext inputs encrypted from a plaintext input by an encryption function using different cryptographic keys are input, wherein the encryption function is selected from a function family having an output space of one or more convex sets. A divergence between the two ciphertext inputs is computed. A membership oracle is executed on the two ciphertext inputs, wherein the two ciphertext inputs are determined to be members of the same convex set of the one or more convex sets if the computed divergence satisfies a separation condition. The two ciphertext inputs are validated to both correspond to the same plaintext input, responsive to determining that the two ciphertext inputs are members of the same convex set, wherein the two ciphertext inputs do not correspond to the same plaintext input if the two ciphertext inputs are not members of the same convex set.

Abstract: In at least one implementation, technology disclosed herein provides a method including generating a plurality of shares of an encryption key such that a combination of shares having a cardinality above a threshold cardinality is sufficient to retrieve data encrypted with the encryption key, distributing the plurality of shares among a plurality of devices, the plurality of devices including one or more disc drive cartridges and one or more printed circuit board assemblies (PCBAs) configured to host one or more of the disc drive cartridges, receiving one or more of the plurality of shares from the plurality of devices, and in response to determining that cardinality of the received one or more of the plurality of shares is above the threshold cardinality, retrieving the data encrypted with the key.

Abstract: In at least one implementation, technology disclosed herein provides a method including generating a plurality of shares of an encryption key such that a combination of shares having a cardinality above a threshold cardinality is sufficient to retrieve data encrypted with the encryption key, distributing the plurality of shares among a plurality of devices, the plurality of devices including one or more disc drive cartridges and one or more printed circuit board assemblies (PCBAs) configured to host one or more of the disc drive cartridges, receiving one or more of the plurality of shares from the plurality of devices, and in response to determining that cardinality of the received one or more of the plurality of shares is above the threshold cardinality, retrieving the data encrypted with the key.