Generating ephemeral key pools for sending and receiving secure communications

Patent metadata

Field	Value
Publication number	US-11316666-B2
Application number	US-201715647576-A
Country	US
Kind code	B2
Filing date	Jul 12, 2017
Priority date	Jul 12, 2017
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A method, system, and non-transitory computer readable medium are described for providing a sender a plurality of ephemeral keys such that a sender and receiver can exchange encrypted communications. Accordingly, a sender may retrieve information, such as a public key and a key identifier, for the first receiver from a local storage. The retrieved information may be used to generate a key-encrypting key that is used to generate a random communication encryption key. The random communication encryption key is used to encrypt a communication, while the key-encrypting key encrypts the random communication key. The encrypted communication and the encrypted random communication key are transmitted to the first receiver.

First claim

What is claimed is:

1. A method comprising:
determining, by a first device and from a computing resource, that one or more encryption keys to establish secure communication with a second device are not available from the computing resource;
in response to the determining, generating, by the first device, a first plurality of asymmetric key pairs comprising a first plurality of private keys and a first plurality of public keys;
assigning, by the first device, a unique identifier to each pair of the first plurality of asymmetric key pairs;
storing the first plurality of private keys and their assigned unique identifiers in a memory of the first device;
transmitting, from the first device, the first plurality of public keys and their assigned unique identifiers to a first server;
in response to the determining, generating, by the first device, a second plurality of asymmetric key pairs comprising a second plurality of private keys and a second plurality of public keys;
assigning, by the first device, a unique identifier to each pair of the second plurality of asymmetric key pairs;
storing the second plurality of private keys and their assigned unique identifiers in the memory;
transmitting, from the first device, the second plurality of public keys and their assigned unique identifiers to the second device;
receiving, by the first device and from the second device, an encrypted peer-to-peer communication, wherein the encrypted peer-to-peer communication comprises an encrypted symmetric key, a public key associated with the second device, and a first unique identifier corresponding to the public key;
recovering, by the first device and using an application identifier associated with an application executing on the first device, the encrypted symmetric key and the first unique identifier from the encrypted peer-to-peer communication;
retrieving, based on the first unique identifier, a private key associated with the public key;
deriving a key-encrypting key, wherein the key-encrypting key is derived according to a key agreement protocol using the private key associated with the public key, the public key associated with the second device, and the application identifier;
decrypting, using the key-encrypting key, the encrypted symmetric key;
decrypting, using the symmetric key, the encrypted peer-to-peer communication; and
deleting, from the memory and based on the decrypting the encrypted peer-to-peer communication, the private key.

2. The method of claim 1 , further comprising:
generating, by the first device, a signature for each of the public keys of the first plurality of asymmetric key pairs;
encrypting, by the first device, the first plurality of public keys, their assigned unique identifiers, and the signature for each of the public keys using a public key of the first server; and
transmitting, from the first device, the first plurality of encrypted public keys, the encrypted assigned unique identifiers, and the encrypted signature for each of the public keys to the first server.

3. The method of claim 2 , further comprising:
encrypting, by the first device and prior to being stored in the memory, each of the first plurality of private keys and their assigned unique identifiers using a local storage key.

4. The method of claim 1 , further comprising:
generating, by the first device, a signature for each of the public keys of the second plurality of asymmetric key pairs;
calculating, by the first device, a first encryption key, wherein the first encryption key is calculated by inputting a first set of pseudorandom bytes into a key derivation function;
encrypting, by the first device, the second plurality of public keys, their assigned unique identifiers, and the signature for each of the public keys using the first encryption key; and
transmitting, from the first device, the second plurality of encrypted public keys, the encrypted assigned unique identifiers, and the encrypted signature for each of the public keys to the second device.

5. The method of claim 4 , further comprising:
encrypting, by the first device, the first encryption key.

6. The method of claim 5 , further comprising:
transmitting, from the first device, the encrypted first encryption key with the second plurality of encrypted public keys, the encrypted assigned unique identifiers, and the encrypted signature for each of the public keys.

7. The method of claim 1 , further comprising:
encrypting, by the first device and prior to being stored in the memory, each of the second plurality of private keys and their assigned unique identifiers using a local storage key.

8. The method of claim 1 , further comprising:
receiving, at the first device, a third plurality of public keys, a unique identifier for each public key in the third plurality of public keys, and a signature for each of the third plurality of public keys from the second device;
validating, at the first device, the signature for each public key in the third plurality of public keys; and
storing, at the first device, the third plurality of public keys and the unique identifier for each public key in the third plurality of public keys when the signatures for each public key in the third plurality of public keys are valid.

9. The method of claim 8 , wherein the signature for each public key in the third plurality of public keys comprises a signature chain.

10. The method of claim 1 , wherein the computing resource is one or more of a key distribution center, a secure communication platform, or a cloud service provider, the computing resource comprising one or more servers.

11. A computing device comprising:
one or more processors; and
memory comprising instructions that, when executed by the one or more processors, cause the computing device to:
determine, from a computing resource, that one or more encryption keys to establish secure communication with a second device are not available from the computing resource;
in response to the determining, generate a first plurality of asymmetric key pairs comprising a first plurality of private keys and a first plurality of public keys;
assign each pair of the first plurality of asymmetric key pairs a unique identifier;
store the first plurality of private keys and their assigned unique identifiers;
transmit, to a first server, the first plurality of public keys and their assigned unique identifiers;
in response to the determining, generate a second plurality of asymmetric key pairs comprising a second plurality of private keys and a second plurality of public keys;
assign each pair of the second plurality of asymmetric key pairs a unique identifier;
store the second plurality of private keys and their assigned unique identifiers;
transmit, to the second device, the second plurality of public keys and their assigned unique identifiers;
receive, from the second device, an encrypted peer-to-peer communication, wherein the encrypted peer-to-peer communication comprises an encrypted symmetric key, a public key associated with the second device, and a first unique identifier corresponding to the public key;
recover, using an application identifier associated with an application executing on the first device, the encrypted symmetric key and the first unique identifier from the encrypted peer-to-peer communication;
retrieve, based on the first unique identifier, a private key associated with the public key;
derive a key-encrypting key, wherein the key-encrypting key is derived according to a key agreement protocol using the private key associated with the public key, the public key associated with the second device, and the application identifier;
decrypt, using the key-encryp

Assignees

• Amazon Tech Inc

Inventors

• Leavy Thomas Michael
• Alwen Joël
• Howell Christopher

Classifications

• H04W12/047

  without using a trusted network node as an anchor · CPC title

• H04L9/3247

  involving digital signatures · CPC title

• H04W12/04

  Key management, e.g. using generic bootstrapping architecture [GBA] · CPC title

• H04L2209/08

  Randomization, e.g. dummy operations or using noise · CPC title

• H04L9/14

  using a plurality of keys or algorithms · CPC title