# US 10,375,037 B2 · Methods and apparatus for efficiently implementing a distributed database within a network

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- Number: US 10,375,037 B2
- Document ID: US10375037B2
- Status: Granted
- Kind: B2
- Application number: 16/032,652
- Filed: 2018-07-11
- Published: 2019-01-17
- Granted: 2019-08-06
- Earliest claimed: 2017-07-11
- Assignees: Swirlds, Inc.
- Applicants: Swirlds, Inc.
- Inventors: Leemon C. Baird, III; Mance Harmon
- Web page: https://patentgrep.com/patent/US10375037B2

## CPC

- G06F 21/6218: {to a system of files or objects, e.g. local or distributed file system or database}
- G06F 16/27: Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
- H04L 9/0869: {involving random numbers or seeds}
- H04L 9/12: Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
- H04L 9/3006: {underlying computational problems or public-key parameters}
- H04L 9/3066: {involving algebraic varieties, e.g. elliptic or hyper-elliptic curves}
- H04L 9/3236: {using cryptographic hash functions}
- H04L 9/3297: {involving time stamps, e.g. generation of time stamps}
- H04L 63/0421: {Anonymous communication, i.e. the party's identifiers are hidden from the other party or parties, e.g. using an anonymizer}
- H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload}
- H04L 63/0442: {wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption (cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30)}
- H04L 63/06: {for supporting key management in a packet data network (cryptographic mechanisms or cryptographic arrangements for key management H04L9/08)}
- H04L 63/061: {for key exchange, e.g. in peer-to-peer networks (cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838)}
- H04W 12/02: Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
- H04L 9/50: {using hash chains, e.g. blockchains or hash trees}
- H04L 67/1097: for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
- H04L 2209/04: Masking or blinding
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

An apparatus includes a processor and a memory operatively coupled to the processor and associated with an instance of a distributed database at a first compute device. The processor is configured to select an anonymous communication path. Each blinded public key from a sequence of blinded public keys associated with the anonymous communication path is associated with a pseudonym of a compute device from a set of compute devices that implement the anonymous communication path. The processor is configured to generate an encrypted message encrypted with a first blinded public key. The processor is configured to generate an encrypted data packet including the encrypted message and a compute device identifier associated with a second compute device. The encrypted data packet is encrypted with a second blinded public key. The processor is configured to send the encrypted data packet to a third compute device.

## Claims

### Claim 1

An apparatus, comprising:
a memory associated with an instance of a distributed database at a first compute device configured to be included within a plurality of compute devices that implement the distributed database via a network operatively coupled to the plurality of compute devices; and
a processor operatively coupled to the memory, and configured to:
select an anonymous communication path associated with: (a) a second compute device from the plurality of compute devices that implement the distributed database, and (b) a set of compute device identifiers, the anonymous communication path defined by a sequence of blinded public keys, each blinded public key from the sequence of blinded public keys associated with a pseudonym of a compute device from a set of compute devices that implement the anonymous communication path;
generate an encrypted message encrypted with a first blinded public key included in the sequence of blinded public keys, the first blinded public key associated with the second compute device, the first blinded public key being defined as a pair (B′, H′) based on a public key defined as a pair (B, H) and a random value (R), the pair (B′, H′) being defined as (B{circumflex over ( )}R, H{circumflex over ( )}R);
generate an encrypted data packet including the encrypted message and a compute device identifier from the set of compute device identifiers, the compute device identifier associated with the second compute device, the encrypted data packet encrypted with a second blinded public key from the sequence of blinded public keys; and
send the encrypted data packet to a third compute device from the set of compute devices that implement the anonymous communication path.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the random value (R) is a first random value (R1), the public key is generated by:
selecting a second random value (R2) from a predefined set of values (G) that is an algebraic group such that R2 is a generator for G;
selecting a third random value (R3) from the predefined set of values (G);
defining the public key as the pair (B, H) based on the second random value (R2) and the third random value (R3), the pair (B, H) being defined as (R2, R2{circumflex over ( )}R3),
the first random value (R1) is selected from the predefined set of values (G), the first random value (R1) being selected such that B{circumflex over ( )}R1 is a generator for G.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein:
the predefined set of values (G) is chosen to be a set of numbers {1, 2, 3, . . . , 2P} for some prime P such that 2P+1 is prime;
a group operator * is defined to be multiplication modulo 2P+1;
an exponentiation is defined to be repeated multiplication modulo 2P+1; and
an element D of G is defined to be a generator if neither D{circumflex over ( )}2 nor D{circumflex over ( )}P are congruent to 1 modulo 2P+1.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the random value (R) is a first random value (R1), the processor is configured to generate the encrypted message (X, Y) by:
selecting a second random value (R2) from a predefined set of values (G) that is an algebraic group; and
encrypting a plaintext message (M) using the first blinded public key (B′, H′) and the second random value (R2) to define an encrypted ciphertext as (X, Y)=(B′{circumflex over ( )}R2, M*H′{circumflex over ( )}R2).

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the random value (R) is a first random value (R1), the processor is configured to blind the encrypted message (X, Y) by using the first blinded public key (B′, H′) to generate a blinded encrypted message (X′, Y′) by:
selecting a second random value (R2) from a predefined set of values (G) that forms an algebraic group; and
defining the blinded encrypted message as (X′, Y′)=(X*(B′{circumflex over ( )}R2), Y*(H′{circumflex over ( )}R2)); and
the processor is configured to generate the encrypted data packet including the blinded encrypted message.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the encrypted data packet is a first encrypted data packet, the anonymous communication path is a first anonymous communication path, and the processor is further configured to:
receive a second encrypted data packet, from the second compute device and via a second anonymous communication path different from the first anonymous communication path; and
decrypt the second encrypted data packet with a private key specific to the first compute device.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the encrypted data packet is a first encrypted data packet, the anonymous communication path is a first anonymous communication path, the set of compute devices that implement the first anonymous communication path is a first set of compute devices, and the processor is further configured to:
receive from the second compute device, a second data packet, via a second anonymous communication path implemented by a second set of compute devices different from the first set of compute devices.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the set of compute device identifiers includes a sequence of encrypted compute device identifiers, each compute device identifier from the sequence of encrypted compute device identifiers encrypted with a different blinded public key selected from the sequence of blinded public keys.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein the set of compute device identifiers includes a non-encrypted compute device identifier.

### Claim 10 (depends on 1)

The apparatus of claim 1, wherein an Internet Protocol (IP) address of at least one compute device from the set of compute devices that implement the anonymous communication path remains undisclosed to the first compute device.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein at least one compute device identifier from the set of compute device identifiers remains undisclosed to a fourth compute device that implements the anonymous communication path, the fourth compute device different from the second compute device and the third compute device.

### Claim 12 (depends on 1)

The apparatus of claim 1, wherein a private key to decrypt messages encrypted with the first blinded public key is specific to the second compute device.

### Claim 13

A non-transitory processor-readable medium comprising code which, when executed by a processor, causes the processor to:
select, at a first compute device, a first random value (R1) from a predefined set of values (G) that is an algebraic group such that R1 is a generator for G;
select a second random value (R2) from the predefined set of values (G);
define a public key as a pair (B, H) based on the first random value (R1) and the second random value (R2), the pair (B, H) being defined as (R1, R1{circumflex over ( )}R2);
send the public key (B, H) such that a second compute device securely provides a message (M) to the first compute device by:
selecting a third random value (R3) from the predefined set of values (G);
encrypting the message (M) using (1) a blinded public key (B′, H′) defined based on the public key (B, H) and (2) the third random value (R3), to define an encrypted ciphertext as (X, Y)=(B′{circumflex over ( )}R3, M*H′{circumflex over ( )}R3); and
sending the encrypted ciphertext (X, Y) to the first compute device;
receive the encrypted ciphertext (X, Y) from the second compute device; and
decrypt the encrypted ciphertext (X, Y) to identify the message (M) using the second random value (R2).

### Claim 14 (depends on 13)

The non-transitory processor-readable medium of claim 13, wherein:
the predefined set of values (G) is chosen to be a set of numbers {1, 2, 3, . . . , 2P} for some prime P such that 2P+1 is prime;
a group operator * is defined to be multiplication modulo 2P+1;
an exponentiation is defined to be repeated multiplication modulo 2P+1; and
an element D of G is defined to be a generator if neither D{circumflex over ( )}2 nor D{circumflex over ( )}P are congruent to 1 modulo 2P+1.

### Claim 15 (depends on 13)

The non-transitory processor-readable medium of claim 13, wherein the code to cause the processor to send the public key includes code to cause the processor to send the public key such that the second compute device securely provides the message (M) to the first compute device by:
blinding the encrypted cypertext (X, Y) by using the blinded public key (B′, H′) to generate a blinded encrypted message (X′, Y′) by:
selecting a fourth random value (R4) from the predefined set of values (G); and
defining the blinded encrypted message as (X′, Y′)=(X*(B′{circumflex over ( )}R4), Y*(H′{circumflex over ( )}R4)); and
generating an encrypted data packet including the blinded encrypted message; and
sending the encrypted ciphertext as the blinded encrypted message to the first compute device.

### Claim 16 (depends on 13)

The non-transitory processor-readable medium of claim 13, wherein the blinded public key is defined by:
selecting a fourth random value (R4) from the predefined set of values (G) such that B{circumflex over ( )}R4 is a generator for G; and
defining the blinded public key as the pair (B′, H′) based on the public key and the fourth random value (R4), the pair (B′, H′) being defined as (B{circumflex over ( )}R4, H{circumflex over ( )}R4).

### Claim 17

A non-transitory processor-readable medium comprising code which, when executed by a processor, causes the processor to:
define an anonymous communication path with a sequence of blinded public keys for a set of compute devices from a plurality of compute devices that implement a distributed database, the set of compute devices define the anonymous communication path, each blinded public key from the sequence of blinded public keys is associated with a pseudonym of a different compute device from the plurality of compute devices that implement the distributed database;
generate a set of compute device identifiers including (1) an unencrypted compute device identifier identifying a compute device from the plurality of compute devices and (2) a sequence of encrypted compute device identifiers, each encrypted compute device identifier from the sequence of encrypted compute device identifiers encrypted with a different blinded public key from the sequence of blinded public keys;
provide the sequence of blinded public keys and the set of compute device identifiers to at least one compute device from the plurality of compute devices such that the at least one compute device can define a message to the processor for sending via the anonymous communication path;
receive, via the anonymous communication path, the message encrypted with a blinded public key from the sequence of blinded public keys; and
decrypt the message with a private key associated with the blinded public key from the sequence of blinded public keys.

### Claim 18 (depends on 17)

The non-transitory processor-readable medium of claim 17, wherein the private key associated with the blinded public key from the sequence of blinded public keys is specific to the processor.

### Claim 19 (depends on 17)

The non-transitory processor-readable medium of claim 17, wherein the at least one compute device is not included in the set of compute devices that implement the anonymous communication path.

### Claim 20 (depends on 17)

The non-transitory processor-readable medium of claim 17, wherein each encrypted compute device identifier from the sequence of encrypted compute device identifiers is uniquely associated with a different compute device from the plurality of compute devices that implement the distributed database.

### Claim 21 (depends on 13)

The non-transitory processor-readable medium of claim 13, wherein the blinded public key is defined by a third compute device.