CN119893515A

CN119893515A - Method and system for safely transmitting data between DH and NFCC

Info

Publication number: CN119893515A
Application number: CN202411852600.0A
Authority: CN
Inventors: 杨传银; 朱述波; 朱恒毅; 潘朝阳; 王涛
Original assignee: Wuxi Rongka Technology Co ltd
Current assignee: Wuxi Rongka Technology Co ltd
Priority date: 2024-12-16
Filing date: 2024-12-16
Publication date: 2025-04-25

Abstract

The embodiment of the present invention discloses a method and system for securely transmitting data between DH and NFCC, the method comprising: before data is transmitted between DH and NFCC, when NFCC is initialized, an asymmetric key pair is generated; when an NFC card enters the field, NFCC sends a first message to DH; DH generates a verification instruction according to the first message and sends it to NFCC; NFCC uses a private key to decrypt the verification instruction to obtain interactive data. The embodiment of the present invention can ensure the security and integrity of interactive data such as keys during transmission. In addition, the session key will be deleted after the NFC card interaction is completed to ensure that it will not be maliciously acquired or restored. That is, the embodiment of the present invention also provides a key destruction mechanism, which can effectively prevent the key from being exposed or abused for a long time.

Description

Method and system for safely transmitting data between DH and NFCC

Technical Field

The invention relates to the technical field of data interaction, in particular to a method and a system for safely transmitting data between DH and NFCC.

Background

At present, more and more smart phones on the market are configured with NFC chips, and equipment capable of reading and writing NFC labels is commonly used in scenes such as entrance guard, payment and the like. NFC card is widely applied to various scenes requiring identity recognition and access control due to convenience, high efficiency, reliability and versatility. Therefore, it is very common to read and write NFC cards using mobile phones.

The flow of data interaction between DH and NFCC is shown in FIG. 1. Because the DH adopts an Android system, the DH is an open environment and is easy to attack by malicious software, data is transmitted in a plaintext form, and if the data is illegally acquired, the safety of the system is threatened.

Disclosure of Invention

The embodiment of the invention aims to provide a method and a system for safely transmitting data between DH and NFCC, which ensure the safety and the integrity of interactive data such as secret keys in the transmission process by adopting an encryption safety mechanism.

To achieve the above object, in a first aspect, an embodiment of the present invention provides a method for securely transmitting data between a DH and an NFCC, including:

Before data transmission is carried out between DH and NFCC, generating an asymmetric key pair when the NFCC is initialized, wherein the asymmetric key pair comprises a public key and a private key;

when the NFC card enters the field, the NFCC sends a first message to the DH;

The DH generates a verification instruction according to the first message and sends the verification instruction to the NFCC, wherein the verification instruction comprises encrypted interaction data;

and the NFCC decrypts the verification instruction by adopting a private key to obtain interaction data.

As a specific implementation of the present application, DH is provided with eSE;

upon initialization of the NFCC, the NFCC specifies that the eSE generate an asymmetric key pair and returns the public key of the asymmetric key pair.

As a specific implementation mode of the application, the first message comprises a notification message, a public key and a random number Rand1, and the DH generates a verification instruction according to the first message, specifically:

the DH receives the notification message and generates a random number Session according to the notification message;

DH adopts the said public key to encrypt the said random number Session;

DH adopts symmetric encryption algorithm and said random number Session to encrypt random number Rand1 and MIFARE card key;

And generating a verification instruction according to the encrypted random number Session, the random number Rand1 and the interaction data.

As a specific implementation manner of the present application, the NFCC decrypts the verification instruction by using a private key to obtain the interaction data, which specifically includes:

The NFCC directly uses or designates eSE to decrypt the verification instruction by using the private key to obtain random number Session;

Decrypting the verification instruction by adopting a random number Session to obtain a random number Rand2;

judging whether the random number Rand2 is the same as the random number Rand 1;

If the verification instruction is the same, decrypting the verification instruction by using a random number Session to obtain interaction data;

if not, an error is returned.

As a preferred implementation manner of the present application, after obtaining the interaction data, the method further includes:

When the NFC card interaction flow is completed or interrupted, the DH and the NFCC destroy the random number Session.

In a second aspect, the embodiment of the application further provides a system for securely transmitting data, which comprises DH and NFCC, wherein the NFCC is used for:

When the NFC card enters the field, the NFCC sends a first message to the DH;

the DH adopts an android system for:

Generating a verification instruction according to the first message, and sending the verification instruction to the NFCC, wherein the verification instruction comprises encrypted interaction data;

The NFCC is also for:

and decrypting the verification instruction by adopting a private key to obtain interactive data.

As a specific implementation manner of the application, the first message comprises a notification message, a public key and a random number Rand1, and the DH is specifically used for:

Receiving the notification message, and generating a random number Session according to the notification message;

Encrypting the random number Session by adopting the public key;

Encrypting the random number Rand1 and interaction data by adopting an SM4 algorithm and the random number Session;

As a specific implementation of the present application, the NFCC is specifically configured to:

decrypting the verification instruction by using the private key by using or designating eSE to obtain a random number Session;

if not, an error is returned.

By implementing the embodiment of the invention, a pair of asymmetric keys is generated during the initialization of the NFCC, and a secure channel is established between the DH and the NFCC to generate a session key. When the interactive data is transmitted, the session key is used for encrypting the information. Therefore, even if the data are intercepted, the original data cannot be directly analyzed, and the safety and the integrity of the interactive data such as the secret key in the transmission process can be ensured.

In addition, the session key is deleted after the NFC card interaction is completed, so that malicious acquisition or recovery is avoided. Namely, the embodiment of the invention also provides a key destruction mechanism which can effectively prevent the key from being exposed or abused for a long time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a flow chart of data interaction between DH and NFCC in the prior art;

fig. 2 is a main flow chart of a method for securely transmitting data between a DH and an NFCC according to an embodiment of the present invention;

FIG. 3 is a first sub-flowchart of the main flowchart shown in FIG. 2;

Fig. 4 is a second sub-flowchart of the main flowchart shown in fig. 2.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The technical terms related to the embodiment of the application are described as follows:

NFC (NEAR FIELD Communication), near field Communication technology

NFCC (NEAR FIELD Communication Controller), short-range wireless communication controller, e.g.

NFC chip

DH (Device host), host, e.g. mobile phone terminal

ESE (embedded Secure Element), embedded security element

Referring to fig. 1, a main flow chart of a method for securely transmitting data between DH and NFCC according to an embodiment of the present invention mainly includes the following steps:

s1, before data transmission is carried out between DH and NFCC, generating an asymmetric key pair when the NFCC is initialized.

S2, when the NFC card enters the field, the NFCC sends a first message to the DH.

S3, the DH generates a verification instruction according to the first message and sends the verification instruction to the NFCC.

The verification instruction comprises encrypted interaction data, the first message comprises a notification message, a public key and a random number Rand1, and the DH generates the verification instruction according to the first message and specifically comprises the following steps:

DH adopts the said public key to encrypt the said random number Session;

DH adopts SM4 algorithm and said random number Session to encrypt random number Rand1 and interactive data;

S4, the NFCC decrypts the verification instruction by adopting a private key to obtain interaction data.

In specific implementation, step S4 includes:

The NFCC uses or appoints eSE to decrypt the verification instruction by using the private key to obtain a random number Session;

if not, an error is returned.

S5, the NFCC and the NFC card interact.

And S6, when the NFC card interaction flow is completed or interrupted, the DH and the NFCC destroy the random number Session.

Two specific implementations are included in the main flow diagram, the first for a common DH and the second for a DH with an eSE. The following will describe each.

A first implementation is shown in fig. 3, comprising the steps of:

(1) The NFCC generates an asymmetric key pair upon initialization, the asymmetric key pair comprising a public key and a private key.

(2) When the NFC card enters the field, the NFCC sends the notification information to the DH along with the public KEY of the KEY and a random number Rand.

(3) The DH receives the notification, generates a random number Session, encrypts the Session using the public key and an asymmetric encryption algorithm, encrypts the MIFARE key and Rand using a symmetric encryption algorithm (e.g., SM4 algorithm) with the Session. And sending a verification instruction of the combination of the encrypted Session, rand and the interactive data key to the NFCC.

It should be noted that, since encryption and decryption efficiency of the symmetric algorithm is far higher than that of the asymmetric algorithm, in general, in terms of selection of the algorithm, people are used to preferentially select the symmetric algorithm DES, AES, SM, SM7, etc., and the signature/verification algorithm selects the asymmetric algorithm RSA, ECC, SM, SM9, etc., but may also be flexibly selected according to needs in some special practical application scenarios. In this embodiment, the DH end is considered to be an open unsafe environment, so an asymmetric algorithm is selected when encrypting Session, and the NFCC needs to generate an asymmetric key first.

(4) The NFCC uses the KEY private KEY to decrypt to obtain Session, then uses Session to decrypt to obtain Rand, judges whether the decrypted Rand is the same as the DH, uses Session to decrypt to obtain interactive data, and returns an error if the decrypted Rand is different from the Rand value transmitted to the DH.

(5) And finishing or interrupting the NFC card interaction flow, and destroying Session by DH and NFCC.

The second implementation is shown in fig. 4, and includes the following steps:

(1) Upon initialization of the NFCC, the designated eSE generates an asymmetric KEY pair KEY, which returns the public KEY.

(3) The DH receives the notice, generates a random number Session, encrypts the Session by using the public key and an asymmetric encryption algorithm, encrypts the interactive data and Rand by using a symmetric encryption algorithm (e.g., SM4 algorithm). And sending a verification instruction of the combination of the encrypted Session, rand and the interactive data to the NFCC.

(4) The NFCC appoints that the eSE uses the private KEY of the KEY to decrypt to obtain the Session, then uses the Session to decrypt to obtain the Rand, judges whether the decrypted Rand is the same as the DH, otherwise returns an error. And finally, decrypting by using Session to obtain interactive data.

In the second implementation, the security may be further improved by performing the asymmetric key pair operation using the eSE.

Based on the same inventive concept, the embodiment of the invention also provides a system for safely transmitting data, which comprises DH and NFCC, wherein the NFCC is used for:

When the NFC card enters the field, the NFCC sends a first message to the DH;

the DH adopts an android system for:

The NFCC is also for:

Further, the first message includes a notification message, a public key, and a random number Rand1, where the DH is specifically configured to:

Encrypting the random number Session by adopting the public key;

Further, the NFCC is specifically configured to:

if not, an error is returned.

It should be noted that, please refer to the foregoing method embodiment, and the detailed description is omitted herein.

While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A method for securely transmitting data between a DH and an NFCC, comprising:

Before data is transmitted between DH and NFCC, an asymmetric key pair is generated when NFCC is initialized; the asymmetric key pair includes a public key and a private key;

When the NFC card enters the venue, the NFCC sends a first message to the DH; the DH uses the Android system;

The DH generates a verification instruction according to the first message, and sends the verification instruction to the NFCC; the verification instruction includes the encrypted interaction data;

The NFCC uses a private key to decrypt the verification instruction to obtain the interaction data.

2. The method for securely transmitting data according to claim 1, wherein the DH has an eSE;

When the NFCC is initialized, the NFCC specifies the eSE to generate an asymmetric key pair and returns the public key of the asymmetric key pair.

3. The method for securely transmitting data according to claim 1 or 2, wherein the first message includes a notification message, a public key and a random number Rand1; and DH generates a verification instruction according to the first message, specifically:

DH receives the notification message and generates a random number Session according to the notification message;

DH uses the public key to encrypt the random number Session;

DH uses a symmetric encryption algorithm and the random number Session to encrypt the random number Rand1 and the interaction data;

A verification instruction is generated according to the encrypted random number Session, random number Rand1 and interaction data.

4. The method for securely transmitting data according to claim 3, wherein the NFCC uses a private key to decrypt the verification instruction to obtain the interaction data, specifically:

The NFCC uses the private key to decrypt the verification instruction to obtain a random number Session;

Decrypt the verification instruction using the random number Session to obtain a random number Rand2;

Determine whether the random number Rand2 is the same as the random number Rand1;

If they are the same, the verification instruction is decrypted using the random number Session to obtain the interaction data;

If different, an error is returned.

5. The method for securely transmitting data according to claim 3, wherein the NFCC uses a private key to decrypt the verification instruction to obtain the interaction data, specifically:

The NFCC specifies the eSE to use the private key to decrypt the verification instruction to obtain a random number Session;

If different, an error is returned.

6. The method for securely transmitting data according to claim 3, characterized in that after obtaining the interactive data, the method further comprises:

When the NFC card interaction process is completed or interrupted, DH and NFCC destroy the random number Session.

7. A system for securely transmitting data, comprising DH and NFCC, wherein the NFCC is used to:

When the NFC card enters the venue, the NFCC sends the first message to the DH;

The DH uses the Android system and is used for:

generating a verification instruction according to the first message, and sending the verification instruction to the NFCC; the verification instruction includes the encrypted interaction data;

The NFCC is also used to:

The verification instruction is decrypted using a private key to obtain interactive data.

8. The system for securely transmitting data according to claim 7, wherein the first message includes a notification message, a public key and a random number Rand1; and the DH is specifically used for:

Upon receiving the notification message, a random number Session is generated according to the notification message;

Encrypt the random number Session using the public key;

The random number Rand1 and the interaction data are encrypted using a symmetric encryption algorithm and the random number Session;

9. The system for securely transmitting data according to claim 7 or 8, wherein the NFCC is specifically used for:

Use or designate eSE to use the private key to decrypt the verification instruction to obtain a random number Session;

If different, an error is returned.

10. The system for securely transmitting data as claimed in claim 7, wherein when the process is completed or interrupted, DH and NFCC destroy the random number Session.