CN112882758B

CN112882758B - iOS device identifier generation method and system

Info

Publication number: CN112882758B
Application number: CN202110115388.XA
Authority: CN
Inventors: 王升富; 白冬立
Original assignee: Beijing Hot Cloud Technology Co ltd
Current assignee: Beijing Hot Cloud Technology Co ltd
Priority date: 2021-01-28
Filing date: 2021-01-28
Publication date: 2022-01-28
Anticipated expiration: 2041-01-28
Also published as: CN112882758A

Abstract

The invention provides a method and a system for generating an iOS device identifier, wherein the method comprises the steps of obtaining iOS parameters and further comprises the following steps: analyzing the iOS parameters, wherein the iOS parameters comprise invariant parameters, non-variable parameters and variable parameters; selecting parameters for generating a CAID from the iOS parameters; and arranging the parameters for generating the CAID to generate the CAID. The unique identification scheme of the CAID equipment has the same effect and function as the IDFA, can accurately mark each part of iOS system equipment, replaces the IDFA with the CAID, and can realize the normal operation of the existing mature service system.

Description

iOS device identifier generation method and system

Technical Field

The invention relates to the technical field of communication networks, in particular to a method and a system for generating an iOS device identifier.

Background

The IDFA (Identifier For Advertising ID) of the iOS system is an official device unique Identifier of the iOS system, and is widely used in a scenario of mobile device unique Identifier by mobile developers. The apple company publishes an iOS14 system on WWDC 2020 (apple developer's congress), in a new system, the acquisition method of the IDFA is adjusted, the default allowed acquisition is modified to the default disallowed acquisition, and after a user manually turns on a corresponding switch, the App can apply for authorization to acquire the IDFA, and finally, the IDFA of the device can be successfully acquired after the user manually turns on the corresponding switch. According to the prediction that after the limit of the IDFA in the iOS14 new system is formally updated, the acquisition rate of the IDFA will be greatly reduced, and a large amount of services based on the unique identifier of the IDFA equipment will face the problem of abnormal operation. At present, no scheme capable of replacing IDFA to become the unique identifier of the apple mobile device appears in the iOS ecology, and the appeal of developers is difficult to meet. In the iOS ecosystem, in addition to the precise device unique identification scheme through IDFA, there is currently a method for fuzzy attribution through IP + UA in some scenarios such as advertising attribution. Compared with the IDFA precise attribution, the IP + UA fuzzy attribution method has the defects that the attribution accuracy is low, equipment cannot be called back to a medium to establish an advertisement effect optimization model, and the like, and the existing service requirements cannot be met.

An article entitled "Apple IDFA replacement scheme SimulateIDFA, more precise identification of device ID" was disclosed on a new wave blog, which was photographed again in 2016, 12 and 30, and shared an IDFA replacement scheme. The method has the defects that the ID generation rule is designed, the ID has no version number mark, the usability of the ID cannot be kept through the upgrading of the generation rule, for example, the ID cannot be updated when some parameters have poor effects, and each developer is difficult to generate the matched ID according to a uniform rule when the algorithm rule is changed.

Disclosure of Invention

In order to solve the above technical problems, the method and system for generating an iOS device identifier according to the present invention can generate a unique CAID device identification scheme, which has the same effect and function as IDFA, can accurately mark each iOS system device, and can realize normal operation of the existing mature service system by replacing IDFA with CAID.

A first object of the present invention is to provide a method for generating an iOS device identifier, including obtaining an iOS parameter, further including the steps of:

step 1: analyzing the iOS parameters;

step 2: selecting parameters for generating a CAID from the iOS parameters;

and step 3: and arranging the parameters for generating the CAID to generate the CAID.

Preferably, the iOS parameters include an invariant parameter, a non-variant parameter, and a variant parameter.

In any of the above embodiments, the invariant parameter is preferably a parameter that is fixed during the production of the device and does not change during lifetime use of the device.

In any of the above-described aspects, the non-variable parameter is preferably a parameter that changes during lifetime use of the device, but often involves a large change in the user's use conditions, and requires manual operation by the user.

In any of the above solutions, it is preferable that the variable parameter is a parameter that can be changed at any time, and the change is different according to the environment where the device is located without manual operation of a user.

In any of the above aspects, it is preferable that the parameters for generating the CAID are composed of the selected invariant parameters and the non-invariant parameters.

In any of the above schemes, preferably, the method for selecting parameters for generating CAIDs includes the following sub-steps:

step 21: sorting the invariant parameters and the non-variable parameters according to the dispersion respectively to generate the dispersion weight of each parameter;

step 22: respectively sequencing the invariant parameters and the non-variable parameters according to the repetition rate to generate the repetition rate weight of each parameter;

step 23: overlapping the dispersion weight and the repetition rate weight of each parameter, and sequencing;

step 24: and selecting a parameter with a small weight value as the parameter for generating the CAID.

In any of the above schemes, preferably, the CAID is in a three-segment type, and includes a first character string, a second character string, and a third character string, and the three-segment character strings are arranged arbitrarily.

In any of the above schemes, preferably, the first string is a version number of the CAID generation rule, and includes at least 2 bits, and each 1 bit is filled with 0 to 9 or a to z.

In any of the above embodiments, preferably, the second character string is composed of the invariant parameter, and the content of the invariant parameter is encrypted by MD5 to obtain N₁Bit string, wherein N₁Is a natural number.

In any of the above embodiments, preferably, the third string is composed of the immutable parameter, and the content of the immutable parameter is encrypted by MD5 to obtain N₂Bit string, wherein N₂Is a natural number.

A second object of the present invention is to provide a system for generating an iOS device identifier, including an iOS parameter obtaining module, further including the following modules:

a parameter analysis module: for analyzing the iOS parameters;

a parameter selection module: selecting a parameter for generating a CAID from the iOS parameters;

an identifier generation module: the CAID generating module is used for arranging the parameters for generating the CAID to generate the CAID;

the system generates the iOS device identifier according to the method as described for the first object.

In any of the above embodiments, preferably, the second character string is composed of the invariant parameter, and the invariant parameter is set to be a value of the second character stringContent is encrypted by MD5 to obtain N₁Bit string, wherein N₁Is a natural number.

The invention provides a method and a system for generating an iOS device identifier, wherein a CAID scheme does not relate to privacy, real-time response, supports device-level data, can be flexibly expanded, can be used for advertisement optimization of an advertisement platform and can meet basic requirements of smooth docking with an existing system, the requirements are also basic requirements which a set of device unique identification scheme should have, and the requirements can be met only if the requirements are met, the requirements of mature application of the existing application scene can be met.

Drawings

Fig. 1 is a flowchart of a preferred embodiment of a method of generating an iOS device identifier according to the present invention.

FIG. 2 is a flow chart of a preferred embodiment of a method for generating an iOS device identifier according to the present invention

Fig. 3 is a block diagram of a preferred embodiment of an iOS device identifier generation system according to the present invention.

Fig. 4 is a schematic diagram illustrating the principle of CAID according to a preferred embodiment of the method for generating an iOS device identifier of the present invention.

Fig. 5 is a flowchart of an embodiment of the CAID server interacting with App data according to the method for generating an iOS device identifier of the present invention.

FIG. 6 is a flow diagram of one embodiment of a CAID for mobile marketing advertisement attribution in accordance with a method of generating an iOS device identifier of the present invention.

Detailed Description

The invention is further illustrated with reference to the figures and the specific examples.

Example one

As shown in fig. 1, step 100 is performed to obtain iOS parameters. The iOS parameters comprise invariant parameters, non-variable parameters and variable parameters; the invariable parameter is a parameter which is fixed during the production of the equipment and can not be changed during the lifetime use of the equipment; the parameters which are not easy to change are parameters which can change in the lifetime use process of the equipment, are usually accompanied by great changes of the use conditions of a user and need manual operation of the user; the variable parameters refer to parameters which can be changed at any time, do not need manual operation of a user, and can be different according to different environments of equipment

Step 110 is executed to analyze the iOS parameters.

And executing a step 120, selecting parameters for generating the CAID from the iOS parameters, and selecting the parameters for generating the CAID which are composed of the invariant parameters and the non-invariant parameters. As shown in fig. 2, the selection method of parameters for generating CAIDs comprises the following sub-steps: executing step 121, sorting the invariant parameters and the non-variable parameters according to the dispersion respectively, and generating the dispersion weight of each parameter; step 122 is executed, the invariant parameters and the non-invariant parameters are respectively sequenced according to the repetition rate, and the repetition rate weight of each parameter is generated; step 123 is executed, the dispersion weight and the repetition rate weight of each parameter are superposed and sorted; step 124 is executed to select the parameter with small weight value as the parameter for generating CAID.

Step 130 is executed to arrange the parameters for generating the CAID to generate the CAID. The CAID is of a three-section type and comprises a first character string, a second character string and a third character string, and the three character strings are randomly arranged. The first character string is the version number of the CAID generation rule, at least comprises 2 bits, and each 1 bit is filled by 0-9 or a-z. The second character string is composed of the invariant parameter, and the content of the invariant parameter is encrypted by MD5 to obtain N₁Bit string, wherein N₁Is a natural number not less than 16. The third character string is composed of the immutable parameter, and the content of the immutable parameter is encrypted by MD5 to obtain N₂Bit string, wherein N₂Not less than 16 is a natural number.

Example two

As shown in fig. 3, the system for generating an iOS device identifier includes an iOS parameter obtaining module 200, a parameter analyzing module 210, a parameter selecting module 220, and an identifier generating module 230.

The iOS parameter obtaining module 200 is configured to obtain iOS parameters, where the iOS parameters include an invariant parameter, a non-variant parameter, and a variant parameter. The invariable parameter is a parameter which is fixed during the production of the equipment and can not be changed during the lifetime use of the equipment; the parameters which are not easy to change are parameters which can change in the lifetime use process of the equipment, are usually accompanied by great changes of the use conditions of a user and need manual operation of the user; the variable parameters refer to parameters which can be changed at any time, do not need manual operation of a user, and are different according to different environments of the equipment.

The parameter analysis module 210 is configured to analyze the iOS parameters, and select the invariant parameters and the non-variant parameters to form the parameters for generating the CAID.

The parameter selection module 220 is configured to select a parameter for generating the CAID from the iOS parameters. The selection method of parameters for generating the CAID comprises the following sub-steps: step 21: sorting the invariant parameters and the non-variable parameters according to the dispersion respectively to generate the dispersion weight of each parameter; step 22: respectively sequencing the invariant parameters and the non-variable parameters according to the repetition rate to generate the repetition rate weight of each parameter; step 23: overlapping the dispersion weight and the repetition rate weight of each parameter, and sequencing; step 24: and selecting a parameter with a small weight value as the parameter for generating the CAID.

The identifier generating module 230 is configured to rank the parameters for generating the CAID, and generate the CAID. The CAID is of a three-section type and comprises a first character string, a second character string and a third character string, and the three character strings are randomly arranged. The first character string is the version number of the CAID generation rule, at least comprises 2 bits, and each 1 bit is filled by 0-9 or a-z. The second character string is composed of the invariant parameter, and the content of the invariant parameter is encrypted by MD5 to obtain N₁A string of bits of the bit string,wherein N is₁Is a natural number. The third character string is composed of the immutable parameter, and the content of the immutable parameter is encrypted by MD5 to obtain N₂Bit string, wherein N₂Is a natural number.

EXAMPLE III

The method aims to solve the problem that the IDFA of the iOS system has low acquisition success rate and cannot normally identify the mobile equipment, so that the cause is inaccurate; in order to solve the problem that the SKAdNetwork cannot meet the requirements of the existing services, a solution of CAID is proposed.

The CAID, China Anonymous ID (CAID), has the following advantages compared to other solutions on the market (as shown in table 1):

TABLE 1

At the beginning of the design of the CAID scheme, basic requirements which do not relate to privacy, real-time response, support of equipment-level data, flexible expansion, application to advertisement optimization of an advertisement platform and smooth docking with the existing system are set, the requirements are also basic requirements which a set of equipment unique identification scheme should have, and the requirements can be met only when the requirements are met, the requirements of mature application of the existing application scene can be met.

CAID inventive principle

The iOS system is convenient for developers to develop products with better experience, and opens a plurality of interfaces for the developers to call, and the developers can call parameters including the storage size of the device, the model of the device, the memory size and the like through the interfaces.

Theoretically, on the same device, the same parameters are obtained at the same time, and the same logic rules are used for encryption processing, so that the obtained results are also the same. Different App developers obey the same rules and will generate the same ID. This ID can be used for device uniqueness validation across apps, and so can be applied in scenarios where ad attribution, risky device identification, DMP tag systems, etc. need to identify devices.

The CAID principle is shown in fig. 4.

Inventive step of CAID

a) Analysis of the parameters obtainable

Through analysis, there are more than 60 parameters that can be obtained on iOS.

These parameters can be categorized as invariant, and invariant.

The invariant parameters are the model of the mobile phone, the total storage capacity of the mobile phone, the memory capacity of the mobile phone and the like. The parameters are fixed during the production of the equipment and cannot be changed in the lifetime use process of the equipment;

non-changeable parameters such as system update time, operator name, country code, etc. These parameters will change in the lifetime usage of the device, but often accompanied by a large change in the user's usage conditions, and require manual operations by the user, such as updating the system version, replacing the SIM card, etc., and thus belong to more stable parameters;

the variable parameters are battery power, address location information, screen brightness, remaining storage capacity, etc. These parameters may change at any time, and these changes do not require manual operation by the user, and may vary depending on the environment in which the device is located.

Examples of the parameters are shown in Table 2.

Parameter(s)	Invariant parameter	Not easy to change parameters	Variable parameter
				Total storage capacity of mobile phone	·
Memory capacity of mobile phone	·
				Mobile phone model	·
Mobile phone system version	·
				System update time accurate to microseconds	·
Core number of CPU	·
				Dominant frequency	·
Resolution ratio	·
				System user name		·^*
Name of operator		·^*
				National code		·^*
System start-up time accurate to second		·^*
				Network type			·
IP			·
				WIFI name			·
More parameters.

TABLE 2

b) Selecting parameters that can be used to generate a CAID

Parameters for generating the CAID take into account the need for privacy protection, the need for higher stability, the need for lower repetition rate, and the need for flexible resettability.

Based on the above requirements, the selection of parameters for generating the CAID needs to be selected from the overall requirements:

invariant parameters: because the model of the equipment is limited, the parameter sets with various invariances are too high in degree, and if only the invariance parameters are selected, the situations that the dispersion is low and the repetition rate is high occur.

Through the repetition degree measurement and calculation of 500 ten thousand devices, under the condition of selecting 8 invariable parameters, the repetition rate exceeds 70 percent, and the repetition rate is too high, so that the requirement of low repetition rate cannot be met;

when the number of the invariant parameters is continuously increased, the decrease of the repetition rate is not obvious because some parameters have correlation, for example, the screen resolution is the same on multiple devices, and the diversity of parameter combinations cannot be obviously improved by increasing the parameters.

Parameters are not easy to change: under the normal condition, parameters which are not easy to change do not change in a certain period, and the stability is better, but the parameters which are not easy to change also have the conditions of lower dispersion and higher repetition rate;

therefore, more consideration is given to the parameters with higher discrete base in the parameters which are not easy to change, such as the system starting time, which are changed after the system is started; through the tracking analysis of the starting time of 500 ten thousand devices, the restarting frequency of the devices is about once in 30 days; but because the system starting time can take seconds, the measured repetition rate is lower than 1/10000;

such as system update time, which changes after a system update; through the analysis of the update frequency of the past iOS system, the update is performed between 12 and 18 times per year, and if the user is completely updated, the change occurs in about 3 to 4 weeks; and the system updating time can be accurately valued to microsecond, the repetition rate is far lower than 1/10000, and the requirement of low repetition rate can be met.

Variable parameters: because the variable parameter has high change rate, if the position information can change along with the change of the position of the user and the screen brightness can change along with the change of the environment brightness when the automatic brightness is started, the requirement of stability cannot be met;

and because variable parameters such as position information are mostly related to user privacy information, the requirement of privacy protection cannot be met.

The volatile parameters cannot be used to generate CAIDs.

Based on the above analysis, the following 9 parameters were finally selected for CAID generation:

1. total storage capacity of mobile phone

2. Mobile phone model

3. Memory capacity of mobile phone

4. Mobile phone system version

5. System update time

6. System user name

7. Name of operator

8. National code

9. System start-up time

c) Formulating rules for generating CAIDs

In order to meet the requirements of the CAID on various aspects of service support, the CAID is designed into a 3-segment form, as follows: xx _ xxxx

1) The 1 st section is the version number of the CAID generation rule, each 1 bit is filled by 0-9, a-z, and the operation is finished from 00 to zz, so that 1296 bit combinations are counted, and the requirements can be met in a long time;

2) in the 2 nd section, 5 parameter contents including total storage capacity of the mobile phone, the model of the mobile phone, the memory capacity of the mobile phone, the system version of the mobile phone and the system updating time are encrypted through MD5 to obtain 32-bit character strings;

3) and in the 3 rd field, 4 parameter contents including system user name, operator name, country code and system restart time are encrypted through MD5 to obtain a 32-bit string.

And finally forming the following combined character string as the generated CAID:

00_6AC3BA5F0D4B9194D3867E2AEC7F5B20_955EAED409D0B4400EB6CBC71094B1F1

compared with other ID generation, the design of CAID has outstanding advantages in compatibility, uniqueness and usability.

1) The design of the version number of the 1 st section improves the compatibility of CAID.

In some cases, when it is necessary to add or delete a parameter for generating a CAID or redefine the parameter, a change in the generation rule is involved.

In order to enable the same device to generate CAIDs corresponding to different version numbers, a developer can generate a plurality of CAIDs corresponding to the version numbers according to the generation rules corresponding to the version numbers, and compatibility among systems applying the generation rules of different versions is realized.

Examples are:

the memory size in the 00 version cannot be obtained after 2 months, the memory size can be abandoned in the 01 version, the screen resolution parameter can be increased at the same time, and developers can simultaneously generate CAIDs of the 00 and 01 versions to correspond to the same equipment. At the moment, other developers generate the CAIDs according to the 00 or 01 versions, and the CAIDs can correspond to the equipment, so that the compatibility of the CAIDs is improved.

2) And 2, the design of the parameters is mainly constant, and the requirements of stability and uniqueness are met.

In the parameters of the section 2, 5 invariant values are used, so that the requirement on stability is well met; the updating time of the system is microsecond, and the requirement on uniqueness can be well met.

3) And the 3 rd section is mainly designed for parameters which are not easy to change, and the usability of the CAID is guaranteed.

In general, when the parameters required for generating the string of the 2 nd segment can be stably obtained, only the 2 nd segment can satisfy the requirement of uniqueness. The 3 rd section is designed to realize the uniqueness of the CAID by the 3 rd section character string under the condition that the parameter in the 2 nd section can not be normally acquired, thereby ensuring the usability of the CAID.

The CAID is used as a unique device identification ID generated in a distributed mode, has less dependence on external third-party services and less transformation on a content system, and has two advantages of applying the CAID to the existing business scene.

The design of the CAID can be mainly applied to the field of effect attribution of mobile advertising marketing. Currently, the precise attribution in the field is mainly performed by means of IDFA.

Precise attribution effects of IDFA

Through the analysis of 500 ten thousand activation data, the successful acquisition rate of the IDFA is about 7%, that is, 7% of users cannot be accurately attributed due to the failure to successfully acquire the IDFA.

The IDFA success acquisition rates for each medium and product vary, with 7% being the result of the total sample size.

The reason for the inability to successfully acquire the IDFA is that the user manually initiates a switch that limits ad tracking.

In addition, about 1% of users will manually reset the IDFA, resulting in IDFA changes, i.e., 1% of users cannot be accurately attributed by resetting the IDFA.

That is, when the IDFA is relied on for precise attribution at present, about 8% of users cannot be precisely attributed.

Precise attribution effects of CAIDs

And similarly, a data test of 500 ten thousand levels is carried out on the CAID, and because the parameters participating in the CAID generation are all acquired through an open system interface, the success rate of the measured CAID generation is 99.99%.

Because there is a systematic restart time in the parameters for generating CAIDs, there is a restart behavior for about 3.6% of users per day, i.e. when 3.6% of CAIDs are used for accurate attribution, attribution errors may be caused by restart reasons.

By means of appointing two times of submitting clicks with the media side, the CAIDs before and after the restart can be obtained for attribution matching.

After optimization by means of secondary reporting, the error rate of the CAID caused by restarting is lower than 1%.

Namely, when accurate attribution is carried out through CAID, the accurate attribution rate exceeds 99%, and compared with IDFA accurate attribution, the effect is improved remarkably.

Example four

The data interaction flow chart of the CAID server and the App server is shown in FIG. 5.

1. And reporting all the events of the SDK, wherein all the events comprise all the parameters + current _ caid.

2. The Server judges whether to start the event, if not, the CAID is not generated; if the event is initiated, current _ caid is generated.

3. Current _ caid is returned to SDK.

4. It is determined whether local current _ caid is empty. If empty, the local current _ caid is updated to the return value.

5. And judging whether the current _ caid is the same as the local current _ caid or not, and if so, not processing.

6. If not, updating the local cached to the original current, and updating the local current _ caid to the return value.

EXAMPLE five

The flow chart for CAID for mobile marketing advertisement attribution is shown in fig. 6.

1. Media side

And installing a media APP, clicking an advertisement, and generating a CAID by the SDK or the Server section.

2. Developer of

And installing an advertiser APP, starting and activating for the first time, and reporting the CAID by the SDK.

The advertiser APP is installed, other events (registration, payment, order) are started, and the SDK reports the CAID.

3. Third party monitoring

Associate CAID information (event backtrack), activate CAID matching attribution, click CAID information (advertisement information).

EXAMPLE six

In this embodiment, the CAID is designed as a 3-segment, as follows: xx _ xxxx

4) The 1 st section is the version number of the CAID generation rule, each 1 bit is filled by 0-9, a-z, and the operation is finished from 00 to zz, so that 1296 bit combinations are counted, and the requirements can be met in a long time;

5) in the 2 nd section, the contents of 6 parameters, namely the total storage capacity of the mobile phone, the model number of the mobile phone, the memory capacity of the mobile phone, the system version of the mobile phone, the system updating time and the CPO core number, are encrypted through MD5 to obtain 32-bit strings;

6) and in the 3 rd field, the contents of the 3 parameters including the system user name, the operator name and the country code are encrypted by the MD5 to obtain a 32-bit string.

00_6AC3BA5F0D4B9194D3867E2AEC7F5B20_955EAED409D0B4400EB6CBC71094B1F1

the number of parameters of the second segment and the number of parameters of the third segment in this embodiment are only examples, and may be adjusted according to actual situations, for example: the number of parameters in the second stage is 4, and the number of parameters in the third stage is 5, but the present invention is not limited thereto.

For a better understanding of the present invention, the foregoing detailed description has been given in conjunction with specific embodiments thereof, but not with the intention of limiting the invention thereto. Any simple modifications of the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention. In the present specification, each embodiment is described with emphasis on differences from other embodiments, and the same or similar parts between the respective embodiments may be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

Claims

1. A method for generating an iOS device identifier includes obtaining an iOS parameter, and is characterized by further including the following steps:

step 1: analyzing the iOS parameters, wherein the iOS parameters comprise invariant parameters, non-variable parameters and variable parameters;

step 2: selecting parameters for generating a CAID from the iOS parameters; the selection of the invariant parameters and the non-invariant parameters constitutes the parameters for generating CAIDs, the method of selecting the parameters for generating CAIDs comprising the sub-steps of:

step 24: selecting parameters for generating the CAID according to the weight value sorting result;

2. The method of generating an iOS device identifier as recited in claim 1, wherein the invariant parameter is a parameter that is fixed at the time of device production and does not change during lifetime use of the device.

3. The method of generating an iOS device identifier as recited in claim 2, wherein the non-changeable parameter is a parameter that does not change for a certain period of time and requires manual operation by a user when the change occurs.

4. The method of claim 3, wherein the variable parameter is a parameter that changes at any time and that changes without manual operation by a user and varies according to the environment in which the device is located.

5. The method of generating an iOS device identifier as recited in claim 4, wherein the CAID is in three segments, including a first string, a second string, and a third string, and the three segments are arbitrarily arranged.

6. The method of generating an iOS device identifier as claimed in claim 5, wherein the first string generates a version number of a rule for the CAID, including at least 2 bits, each 1 bit being filled with 0-9 or a-z.

7. The iOS device identifier generation method according to claim 6, wherein the second character string is constituted by the invariant parameter, and a content of the invariant parameter is encrypted by MD5 to obtain N₁Bit string, wherein N₁Is a natural number.

8. The method of generating an iOS device identifier as claimed in claim 7, wherein the third string is composed of the immutable parameter, and the content of the immutable parameter is encrypted by MD5 to obtain N₂Bit string, wherein N₂Is a natural number.

9. An iOS device identifier generation system comprises an iOS parameter acquisition module, and is characterized by further comprising the following modules:

a parameter analysis module: for analyzing the iOS parameters;

a parameter selection module: selecting a parameter for generating a CAID from the iOS parameters; the selection method of parameters for generating the CAID comprises the following sub-steps:

an identifier generation module: and the CAID generating module is used for arranging the parameters for generating the CAID and generating the CAID.