SIGNED ENVELOPE ENCRYPTION

• US 20170171219A1
• Filed: 12/11/2015
• Published: 06/15/2017
• Est. Priority Date: 12/11/2015
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Campagna, Matthew John
• Granted Patent: US 10,412,098 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• 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 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• CPC Class Codes: H04L 9/321 involving a third party or a trusted authority
• 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: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Clients within a computing environment may establish a secure communication session. Sometimes, a client may trust another client to read, but not modify, a message. Clients may utilize a cryptography service to generate a message protected against improper modification. Clients may utilize a cryptography service to verify whether a protected message has been improperly modified.

Claims

1. A system, comprising:

a first computer system comprising;

a first one or more processors; and

first memory that stores executable instructions that, as a result of being executed by the first one or more processors, causes the first computer system to;

generate a first ciphertext based at least in part on a message by obtaining a cryptographic data key and encrypting at least the message using the data key;

generate a digitally signed payload that includes the first ciphertext and a digital signature generated using at least the first ciphertext and a private key; and

obtain an authenticated payload that includes a second ciphertext based at least in part on the data key, a public key that corresponds to the private key, and an authentication tag verifiable using data that includes at least the data key and the public key; and

a second computer system comprising;

a second one or more processors; and

second memory that stores executable instructions that, as a result of being executed by the second one or more processors, causes the second computer system to;

receive the digitally signed payload and the authenticated payload;

obtain the data key and a key identifier based on at least the second ciphertext, the public key, and the authentication tag;

verify that the key identifier matches an expected key identifier associated with the first computer system and that the digital signature is valid; and

obtain the message by decrypting the first ciphertext using the data key.

2. The system of claim 1, wherein:

obtaining the second ciphertext is further based on additional authenticated data;

the generated authenticated payload further includes the additional authenticated data; and

obtaining the data key and the key identifier is further based on the additional authenticated data.

3. The system of claim 1, wherein:

generating the first ciphertext is based on encrypting at least the message and the public key; and

the second memory further stores executable instructions that causes the second computer system to obtain the public key based on at least the second ciphertext and the authentication tag.

4. The system of claim 1, wherein the private key is an elliptic curve private key, and the public key is an elliptic curve public key.

5. A computer-implemented method, comprising:

under the control of one or more computer systems configured with executable instructions,

generating a first ciphertext based at least in part on a message by obtaining a cryptographic data key and encrypting at least the message using the data key;

generating, using an asymmetric private key, a digital signature based at least in part on the first ciphertext;

generating a digitally signed payload including at least the first ciphertext and the digital signature;

requesting, to a cryptography service, an authenticated encryption by providing at least the cryptographic data key and an asymmetric public key that corresponds to the asymmetric private key, wherein at least the cryptographic data key is indicated to be encrypted;

receiving, in response to the request for the authenticated encryption, a second ciphertext and an authentication tag;

generating an authenticated payload including at least the second ciphertext, the asymmetric public key, and the authentication tag; and

making available, to another computer system, at least the digitally signed payload and the authenticated payload.

6. The computer-implemented method of claim 5, wherein:

requesting the authenticated encryption further includes providing additional authenticated data; and

the authenticated payload further includes the additional authenticated data.

7. The computer-implemented method of claim 5, wherein the asymmetric private key is an elliptic curve private key, and the asymmetric public key is an elliptic curve public key.

8. The computer-implemented method of claim 5, wherein a web API request is used to request the authenticated encryption.

9. The computer-implemented method of claim 5, wherein requesting the cryptography service perform the authenticated encryption further includes indicating the asymmetric public key is to be encrypted.

10. The computer-implemented method of claim 6, wherein requesting the authenticated encryption further includes providing a nonce.

11. The computer-implemented method of claim 10, wherein the authenticated encryption is AES-CCM or AES-GCM encryption.

12. The computer-implemented method of claim 5, wherein at least the digitally signed payload and the authenticated payload are made available by transmitting, in one or more TCP packets, the digitally signed payload and the authenticated payload.

13. The computer-implemented method of claim 5, wherein a web API request is used to obtain, from the cryptography service, the cryptographic data key.

14. A non-transitory computer-readable storage medium having stored thereon executable instructions that, as a result of being executed by one or more processors of a computer system, cause the computer system to at least:

receive a protected message comprising;

a digitally signed payload further comprising a first ciphertext and a digital signature over the first ciphertext; and

an authenticated payload further comprising a second ciphertext, an asymmetric public key, and an authentication tag;

request, to a cryptography service, an authenticated decryption of the second ciphertext by providing at least the second ciphertext, the asymmetric public key, and the authentication tag;

receive, in response to the request for the authenticated decryption, at least a cryptographic data key and a key identifier;

verify that the key identifier matches an expected key identifier associated with an expected client and that the digital signature of the digitally signed payload is valid; and

obtain a message by decrypting, using the cryptographic data key, the first ciphertext of the digitally signed payload.

15. The non-transitory computer-readable storage medium of claim 14, wherein the asymmetric public key is an elliptic curve public key.

16. The non-transitory computer-readable storage medium of claim 14, wherein the protected message further comprises the asymmetric public key.

17. The non-transitory computer-readable storage medium of claim 14, wherein a web API request is used to request the authenticated decryption.

18. The non-transitory computer-readable storage medium of claim 14, wherein the instructions further comprise instructions that, as a result of being executed by the one or more processors, cause the computer system to:

receive, in response to the request for the authenticated decryption, at least the cryptographic data key, the asymmetric public key, and the key identifier.

19. The non-transitory computer-readable storage medium of claim 14, wherein the cryptographic data key is a symmetric cryptographic key.

20. The non-transitory computer-readable storage medium of claim 14, wherein:

the message is obtained after the digital signature is verified;

the digital signature is verified after receiving at least the cryptographic data key and the key identifier; and

the digital signature is verified after verifying the key identifier matches the expected key identifier associated with an expected client.

21. The non-transitory computer-readable storage medium of claim 14, wherein the protected message is received as part of one or more TCP packets.