Encrypt shared data with an aggregate key derived from multiple crypto keychains
In an implementation, all individual data owner key encryption keys (KEKs) are concatenated, as a concatenated key, to form a single longer key. A key derivative function (KDF) is applied to the concatenated key to derive an aggregateKey of a certain target property. Policy-as-code is applied to verify a current validity/authority of the aggregateKey on data of an individual data owner to allow any operations on the data of an individual data owner.
1. A computer-implemented method, comprising:
concatenating, as a concatenated key, all individual data owner key encryption keys (KEKs) to form a single longer key;
applying, to the concatenated key, a key derivative function (KDF) to derive an aggregateKey of a certain target property; and
applying policy-as-code to verify a current validity/authority of the aggregateKey on data of an individual data owner to allow any operations on the data of an individual data owner, wherein, as long as an individual data owner's KEK remains valid, the aggregateKey is usable to encrypt/decrypt each individual data owner's data using each individual data owner's data encryption key (DEK) while another individual data owner's invalid KEK renders the aggregateKey unusable to encrypt/decrypt the another individual data owner's data using the another individual data owner's DEK.
2. The computer-implemented method of claim 1 , wherein the concatenated key inherits properties of its input individual keys, while remaining agnostic to key types and sizes of input individual keys.
3. The computer-implemented method of claim 1 , comprising generating and logging a new version of the aggregateKey whenever an individual data owner changes their associated KEK.
4. The computer-implemented method of claim 1 , wherein security properties of the aggregateKey are tied to properties of the KDF and entropy of all individual data owner KEKs.
5. The computer-implemented method of claim 1 , wherein the certain target property is decided by an application based on a desired entropy and key length.
6. The computer-implemented method of claim 1 , wherein an aggregateKey can be concatenated with a KEK or other aggregateKey to form another aggregateKey.
7. The computer-implemented method of claim 1 , wherein the individual data owner KEKs are crypto keychains.
8. A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:
concatenating, as a concatenated key, all individual data owner key encryption keys (KEKs) to form a single longer key;
applying, to the concatenated key, a key derivative function (KDF) to derive an aggregateKey of a certain target property; and
applying policy-as-code to verify a current validity/authority of the aggregateKey on data of an individual data owner to allow any operations on the data of an individual data owner, wherein, as long as an individual data owner's KEK remains valid, the aggregateKey is usable to encrypt/decrypt each individual data owner's data using each individual data owner's data encryption key (DEK) while another individual data owner's invalid KEK renders the aggregateKey unusable to encrypt/decrypt the another individual data owner's data using the another individual data owner's DEK.
9. The non-transitory, computer-readable medium of claim 8 , wherein the concatenated key inherits properties of its input individual keys, while remaining agnostic to key types and sizes of input individual keys.
10. The non-transitory, computer-readable medium of claim 8 , comprising generating and logging a new version of the aggregateKey whenever an individual data owner changes their associated KEK.
11. The non-transitory, computer-readable medium of claim 8 , wherein security properties of the aggregateKey are tied to properties of the KDF and entropy of all individual data owner KEKs.
12. The non-transitory, computer-readable medium of claim 8 , wherein the certain target property is decided by an application based on a desired entropy and key length.
13. The non-transitory, computer-readable medium of claim 8 , wherein an aggregateKey can be concatenated with a KEK or other aggregateKey to form another aggregateKey.
14. The non-transitory, computer-readable medium of claim 8 , wherein the individual data owner KEKs are crypto keychains.
15. A computer-implemented system, comprising:
one or more computers; and
one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations comprising:
concatenating, as a concatenated key, all individual data owner key encryption keys (KEKs) to form a single longer key;
applying, to the concatenated key, a key derivative function (KDF) to derive an aggregateKey of a certain target property; and
applying policy-as-code to verify a current validity/authority of the aggregateKey on data of an individual data owner to allow any operations on the data of an individual data owner, wherein, as long as an individual data owner's KEK remains valid, the aggregateKey is usable to encrypt/decrypt each individual data owner's data using each individual data owner's data encryption key (DEK) while another individual data owner's invalid KEK renders the aggregateKey unusable to encrypt/decrypt the another individual data owner's data using the another individual data owner's DEK.
16. The computer-implemented system of claim 15 , wherein the concatenated key inherits properties of its input individual keys, while remaining agnostic to key types and sizes of input individual keys.
17. The computer-implemented system of claim 15 , comprising generating and logging a new version of the aggregateKey whenever an individual data owner changes their associated KEK.
18. The computer-implemented system of claim 15 , wherein security properties of the aggregateKey are tied to properties of the KDF and entropy of all individual data owner KEKs.
19. The computer-implemented system of claim 15 , wherein the certain target property is decided by an application based on a desired entropy and key length.
20. The computer-implemented system of claim 15 , wherein the individual data owner KEKs are crypto keychains.