Secure file transfer

• US 9,590,958 B1
• Filed: 06/22/2016
• Issued: 03/07/2017
• Est. Priority Date: 04/14/2016
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Wickr Inc. (Amazon.com, Inc.)
• Inventors: Sugar, David A., Kasabwala, Dipakkumar R., Grzybowski, Ernest W., Howell, Christopher A., Leavy, Thomas Michael
• Primary Examiner(s): Schwartz, Darren B
• Application Number:
  US15/190,132
• Time in Patent Office: 258 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: H04L 12/1827 Network arrangements for conference optimisation or adaptation
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 63/0876 based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]

Abstract

The present disclosure describes techniques for storing encrypted files in a secure file repository and transferring those encrypted files to one or more recipients. A user selects a file to upload to a secure file repository. A secure collaboration app on the user'"'"'s device generates a first encryption key that is used to encrypt the file. The encrypted file is then uploaded to the secure file repository, which provides the secure collaboration app with a random file name and a location of the encrypted file. The secure collaboration app updates locally stored metadata of the first encrypted file. To securely transfer the file, the user generates a second encryption key, encrypts the metadata with the second encryption key, and transmits the encrypted metadata to one or more receivers. The one or more receivers decrypt the encrypted metadata and use the decrypted metadata to retrieve the file and decrypt it.

Claims

1. A system, comprising:

a processor configured to;

obtain a first file to upload to a secure file repository;

generate a first encryption key, wherein the first encryption key is generated at least in part by obtaining ephemeral environmental noise from a kernel operation executing on a sender device;

generate a random file name for the first file, wherein the random file name is a universally unique identifier;

encrypt the first file via an encryption algorithm using the first encryption key;

assign the first encrypted file the generated random file name;

upload the first encrypted file to the secure file repository;

receive, from the secure file repository, a location of the first encrypted file and the random file name assigned to the first encrypted file by the secure file repository;

update metadata associated with the first encrypted file, including at least one of the first encryption key, the location of the first encrypted file on the secure file repository, and the random file name assigned to the first encrypted file;

generate a second encryption key;

encrypt the metadata associated with the first encrypted file, including the first encryption key, using the second encryption key; and

transmit, in a first communication, the encrypted file metadata to one or more receivers of the first encrypted file; and

a memory coupled to the processor and configured to provide the processor with instructions.

2. The system of claim 1, wherein the first encryption key is generated by applying multiple rounds of a hash function to a first set of pseudorandom bytes derived from a sender'"'"'s device.

3. The system of claim 1, wherein the encryption algorithm is a symmetric encryption algorithm.

4. The system of claim 1, wherein the secure file repository is a third-party file repository.

5. The system of claim 1, wherein the second encryption key is generated by applying multiple rounds of a hash function to a second set of pseudorandom bytes derived from a sender'"'"'s device.

6. The system of claim 1, wherein the processor is further configured to:

encrypt the second encryption key with a key-encrypting key unique to each of the one or more receivers;

encrypt the encrypted second encryption key with a device key unique to each of the one or more receivers to produce a twice-encrypted second encryption key; and

compose the first communication by encapsulating the encrypted file metadata in the payload of the first communication and the twice-encrypted second encryption key in the header of the first communication.

7. A method comprising:

obtaining a first file to upload to a secure file repository;

generating a first encryption key, wherein the first encryption key is generated at least in part by obtaining ephemeral environmental noise from a kernel operation executing on a sender device;

generating a random file name for the first file, wherein the random file name is a universally unique identifier;

encrypting the first file via an encryption algorithm using the first encryption key;

assigning the first encrypted file the generated random file name;

uploading the first encrypted file to the secure file repository;

receiving, from the secure file repository, a location of the first encrypted file and the random file name assigned to the first encrypted file by the secure file repository;

updating metadata associated with the first encrypted file, including at least one of the first encryption key, the location of the first encrypted file on the secure file repository, and the random file name assigned to the first encrypted file;

generating a second encryption key;

encrypting the metadata associated with the first encrypted file, including the first encryption key, using the second encryption key; and

transmitting, in a first communication, the encrypted file metadata to one or more receivers of the first encrypted file.

8. The method of claim 7, wherein the first encryption key is generated by applying multiple rounds of a hash function to a first set of pseudorandom bytes derived from a sender'"'"'s device.

9. The method of claim 7, wherein the encryption algorithm is a symmetric encryption algorithm.

10. The method of claim 7, wherein the secure file repository is a third-party file repository.

11. The method of claim 7, wherein the second encryption key is generated by applying multiple rounds of a hash function to a second set of pseudorandom bytes derived from the sender'"'"'s device.

12. The method of claim 7, further comprising:

encrypting the second encryption key with a key-encrypting key unique to each of the one or more receivers;

encrypting the encrypted second encryption key with a device key unique to each of the one or more receivers to produce a twice-encrypted second encryption key; and

composing the first communication by encapsulating the encrypted file metadata in the payload of the first communication and the twice-encrypted second encryption key in the header of the first communication.

13. A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor, perform the steps of:

obtaining a first file to upload to a secure file repository;

generating a first encryption key, wherein the first encryption key is generated at least in part by obtaining ephemeral environmental noise form a kernel operation executing on a sender device;

generating a random file name for the first file, wherein the random file name is a universally unique identifier;

encrypting the first file via an encryption algorithm using the first encryption key;

assigning the first encrypted file the generated random file name;

uploading the first encrypted file to the secure file repository;

receiving, from the secure file repository, a location of the first encrypted file and a random file name assigned to the first encrypted file by the secure file repository;

updating metadata associated with the first encrypted file, including at least one of the first encryption key, the location of the first encrypted file on the secure file repository, and the random file name assigned to the first encrypted file;

generating a second encryption key;

encrypting the metadata associated with the first encrypted file, including the first encryption key, using the second encryption key; and

transmitting, in a first communication, the encrypted file metadata to one or more receivers of the first encrypted file.

14. The non-transitory computer readable medium of claim 13, wherein the first encryption key is generated by applying multiple rounds of a hash function to a first set of pseudorandom bytes derived from a sender'"'"'s device.

15. The non-transitory computer readable medium of claim 13, wherein the encryption algorithm is a symmetric encryption algorithm.

16. The non-transitory computer readable medium of claim 13, wherein the secure file repository is a third-party file repository.

17. The non-transitory computer readable medium of claim 13, wherein the second encryption key is generated by applying multiple rounds of a hash function to a second set of pseudorandom bytes derived from the sender'"'"'s device.

18. The non-transitory computer readable medium of claim 13, further comprising instructions for:

encrypting the second encryption key with a key-encrypting key unique to each of the one or more receivers;

encrypting the encrypted second encryption key with a device key unique to each of the one or more receivers to produce a twice-encrypted second encryption key; and

composing the first communication by encapsulating the encrypted file metadata in the payload of the first communication and the twice-encrypted second encryption key in the header of the first communication.