I. Functions of ID card JAVA s≥£mart card

1. ID card personal information s¥•torage

(1) Information stored in the ID card

The personal information stor≤♦ed on the ID card is very ric↕★'h, including basic identity i≤÷≈nformation, biometric informat★ ®ion, etc. This information is Ω≈collected and stored in the chip duriγδ>¶ng the production proces $×≈s of the ID card for subsequent re♥£βφading and verification✘☆>.

l Basic identity information :

n Name: The ID card clearly states ∑<→the individual’s name, which is th"δ→e basis for identity identificat✔↑₩ ion.

n Gender: The ID card will indicate t☆φ₹he individual's gender so tha₩→t it can be distinguished if necessary.↓  £

n Ethnicity: The ID card δ±✔records an individual’s ethnic informat★→ion, reflecting respec₩∏t for a multi-ethnic counφ"≥try.

n Date of Birth: This is one o​★♥ f the most important i•©₹±nformation on an ID card an±Ωd is used to determine an ind®λ€ividual's age an‍×d birthday.

n Address: The ID card record>←αs an individual’s perm±₩anent residence registrat×↓✘≥ion address for easy household regβε&istration management.

n Citizen ID number: The ID number ×±‍is a unique, lifelong identity code fo∏♥×r every citizen. It consisδ §ts of 18 digits, representing‌ ←> information such as area code,¶÷✘ date of birth and sequence code.

l Biometric Information :

n Fingerprint: Modern ID cards gen≤δerally collect and store personal‍Ω fingerprint informationσ$ for identity recognition a ™nd verification.

n Iris: Some advanced ≠εID cards may also contain iris informat®ε‌♣ion to further improve the ®✔accuracy and security of ideα• ≈ntity recognition.

l Additional Information :

n Photo: A photo of the individua  l is also printed onδ≈ the ID card, which is matched to ≤ Ω$the stored chip information for vi✔φ$sual identification.

n Issuing authority: records the issuing★→₽> unit of the identity card to facilit'↔↓>ate document management and inquir∏Ω∞y.

n Validity period: The ID card has₹•✘ a validity period and needs toΩ≤Ω→ be reissued after it expires.♥♣

( 2 ) ID card information storage and ✔αreading technology

l Information storage technology :

n Chip storage : The chip contains mu$∏←φltiple storage units that caε&"n partition and store different£♠ types of personal informatio∏'n. This information is stored using$≈♥↓ a specific encoding method an♠γ•<d encryption algorithm to en☆₹'$sure data integrity and security.

n Magnetic stripe storag®≈€e (early technology): ≈εAlthough modern ID card‍©€ s generally use chip technology, som¥♠e early or special do≈πcuments may still use magnetic ↑✔​♦stripes to store information. The inf ©ormation on the magnetic stripe is rec←πorded through a specifi→≥ c magnetization process€γ€, but it is easily damaged ∞λ♣♦by external magnetic fields.&$

l Information reading techno§γ≤★logy :

n Contactless reading : Modern ID cards us>®★e contactless IC card techφ¥ nology. The reader commun$≈icates with the chip through r'  adio frequency signals and can re‍‍✘φad information without physicaλγ l contact. This method has the∞•€© advantages of fast reading sp>↕✘ eed, convenient use, and easy sto↓©rage.

n Contact reading (early technology): Eσ¥≤ arly ID cards or some special docum§‍₹ents may use contact reading, which ©©α≥requires inserting the card into t•÷he card reader for reading. This metho§∑εd is relatively cumbersome and ea  γsily affected by physical wear and tea∏↓₽αr.

l Information Verification and Security :

n Encryption algorithm : The chip uses a specific eφ§®∑ncryption algorithm to encr₹÷ypt, store and transmit infor§±↔εmation to ensure the security of i§§★nformation during storage and &¶±reading.

n Security authenticatio ←α∑n mechanism : ID cards need to undergo se→∏"σcurity authentication ÷¥Ωwhen reading information, ensu>→‍₹ring that only authorized de×✔ vices can read the information in th↔✘₩♦e chip. This further enhances the ✔<security of the information.

n Anti-counterfeiting tec®♣hnology : The ID card adopts a var•♣↓$iety of anti-counterfeiting technologi♣≤₩πes, such as laser anti-®®counterfeiting and anti-↑☆•±counterfeiting labels, ≠σ to prevent forgery and tampering.

( 3 ) Information management and a‌↓↕pplication of ID cards

The information managemγ ×÷ent of ID cards involves m↕☆≠ultiple links, including i§≠<★nformation collection, storage, query≥ε¶≠ and use, etc. These®♠ links need to use moderΩπ÷n information technology to β♠ ♥ensure the accuracy and security of inf¥βπormation.

l Information Collection :

n Digital photography : The photo of the ID card ₩♥¶is captured using digital phot βography technology t≥"o ensure the clarity a™<☆♥nd accuracy of the photo.

n Fingerprint collection : Modern ID cards require fingerprint & "£information to be collected, us♣ ≠ually using a fingerprint colle₽₩≠​ctor and storing the fingerprγ≠☆↓int information in a c←♥hip.

n Collection of other biome<™∑≈tric information : Other biometric information such as i×↓→™ris can also be colle>≈cted as needed.

l Information storage and management↓≈β :

n Database technology : ID card information is ★×₹φstored in the database ‌÷±₽for quick query and management. The da≥‌<>tabase system uses advφ∞©anced encryption technology and sec∑<✔urity authentication mechanisms ‌$ to ensure the security of inf'"ormation.

n Network technology : ID card information can be remotely qπ∏'ueried and verified through the Inφ&£ternet, improving the conveni↕♦¶αence and security of information.

l Information query and use :

n Public security agency inq✔¶uiry : Public security agenc↓÷ ies can quickly inqu¥₩×γire about identity card informε© ✔ation through the interna→→ €l network for household regist☆>ration management, crime inve↓€♠₽stigation, etc.

n Administrative depar∞™tment inquiry : Other administrative departments suc←β♥h as education, medical c β←are, etc. can also query ID ♠∞≠♥card information throu•$gh authorization for the processing of £δrelated business.

n Personal inquiry : Individuals can also inquire abo>&ut their ID card informati÷↕on through designated cha→∑♦nnels, such as through the ofβ£ ≥ficial website or APP of the public sec≠∞♠"urity department.

l Smart document management :

n Smart ID card management cabinet : Some units or institutions use β smart ID card management cabinets to ∏®↕≠store and manage a large amount of ID¥≠ card information. This equipmeσ®nt uses modern information tech∞∏π nology to achieve safe s®♠♣‌torage, convenient access and efficien‌εt management of ID cλδ☆ards.

n Fingerprint recogniti≈♦‍ on/face recognition : The smart document managemen&₽t cabinet uses finge‌<£♣rprint recognition or face re∏↓cognition technology to≥ε☆ verify identity and ensure the•₩" uniqueness and securit ×γy of document access.

n Hierarchical authority management : Administrators can assign di±λ‌fferent access rights to diffe‌≠rent users based on employee positions,φ‍ departments, etc., ensuring that™☆× only authorized personnel can access d£→esignated documents.

n Remote monitoring and operation : Administrators can view the usage of÷λ the ID cabinet in real time through"β the background system, includ♠ ₹©ing the current status, access records,→©≠¶ number of ID cards, etc., and ≈©'≥support remote unlocking,&←✘ permission management, data que<£ry and other functions.

 2. ID card authentication♥≤☆∞

( 1 ) How the ID card authentication fun≤  ction works

The identity authentication functiα$<on of the ID card mainly relies on★φ‌® its built-in chip technolo↕®®×gy and advanced encryption algorith÷&ms. Modern ID cards, especiall¶♥☆y the second-generation ID ✔¥™cards, generally use contactless IC ca ∏ σrd technology, that is, bu ₩Ω™ilt-in RFID chips. This  →‍₩chip contains modules such as hiγ♦gh-speed radio frequency interface σ, control unit and electricall©¥y erasable programmable ≠•read-only memory (EEPROM≥©★), which can store a larg®♣e amount of personal ₩¥information and encrypt an‌©© d store and transmit it t☆©"hrough specific encryption ​♦∑algorithms.

When the ID card is clo↓"→↓se to the card reader≈¥, the card reader will send out a radio<↓♦ frequency signal to communicate wit ≥πh the chip. After the chiσ p receives the signal, it will deco×÷de and verify it. If the verifica<™≥tion is successful, t€δ‌γhe card reader will re★←ad the personal information stored inδ✘ the chip and perform furthe∏★r processing and veriε↑"fication. In the who​€ le process, the encryption algor♥€σithm plays a vital roδ↔" le, which ensures the integri∏¥≤ty and security of the information and<₹&₩ prevents the tamperin♣↔εg and leakage of the informa€$<₩tion.

( 2 ) ID card identity verification p↔♠↔rocess

Information reading :

o When the ID card is b‍≥rought close to the r ♠ eader, the reader sends ¥₹§out a radio frequency sign☆€γal to activate the chip÷♦.

o After the chip receives the£±€ signal, it decodes ★£→and extracts the personal infor$​mation stored in the chip.

Information verification :

o The card reader compares th‍•e personal information it r±δ'eads with the preset verification r≤∏•ules.

o These validation rules may include✔≈ consistency checks on basic informatλ×ion such as name, geβ¥←nder, date of birth, ₹→γ←citizen identification number, etc.

o For some advanced verif&&ication scenarios, it may also π¥φ<involve the comparison of bi↔∑↓★ometric information such as fingerprint• φ¶s and irises.

Results feedback :

o If the personal info•★φ∑rmation is consistent with t≤'he verification rules, the card reade‌‍♦r will output a verifi≈$cation result.

o If the personal information is÷↓ inconsistent with the verification rαε<ules, the card reader wi☆₽☆ll output a verification failure result☆  and may prompt an error message.

Record log :

o Whether the verification is suc÷∑cessful or failed, the card reader wilγ♦l record the corresponding∞  log information.

o These log information includes ver♣§ification time, verification resul≈Ωts, personal information, etc✘¥<., which are used for subsequent analy‌÷sis and auditing.

3. JAVA program execution

( 1 ) JAVA program can realize the<<✘ identity card functi ₽×on

‌Read ID card information‌:

Using JAVA's HTTP reα¥∞γquest tool or a dedicated card ↔∞ λreader library, you can read the iφ±nformation on the ID card, including nπ$ame, gender, date of ↑  birth, address, biometric inf₩•↕☆ormation, etc.

‌Verify identity information‌'λ₩:

By calling the ID card real-name autheσ‌↓♥ntication API interface ‌Ωor the local verificatio‌₹↑™n algorithm, the read ID card in"÷©formation can be veri•β♥→fied. The verification process i¶♣ncludes comparison wi☆™th the official database, matching oδ♦↔f biometric informat¶®ion, etc.

‌Processing identity inf∞♠£ormation‌:

According to the verification♠✔σ  results and business requiremen↔¥←ts, the JAVA program can process the I✘•D card information. For example, the v π↓erified ID card information is stored₩×' in the database, or the corresponding<≠∏ user account is gene♠ ≠€rated.

‌Integrate into other→Ω business systems‌:

JAVA programs can integrat₽'e the reading and ve♥$rification functions™α of ID cards into oth€≠π✘er business systems. For examp©©​le, in scenarios such as user registr♠₩Ωσation, payment verificatio πα‌n, and financial risk♦★ control, the authenticity of•≥ user information and the security  ™↑of transactions can be ensured by calli ₽'ng the relevant function >s of the ID card.

( 2 ) Steps to implement ID card re¥♠★£cognition in Java

To implement ID card recoπ♦©gnition in Java, you usually ne∞≠$δed to use some open source OCR libr✔ "≥aries, such as Tessera↑'<ct OCR. The following are basiσ↓☆αc implementation steps:

l Prepare the development environmε'ent : First, you need to p₽♥↔repare the Java develop∑ ¥‌ment environment, su​↔ch as installing the JDK (Java Devel¥γ≈ opment Kit) and configuring related en•×↑ vironment variables.

l Download and install Tesseract OC<α™R engine : Tesseract OCR is an open sourc§✘e OCR engine that is widely a÷$∞dopted for its high accuracy a↔±™nd performance. You can get the ♥<∏≈installation package fro ≥<m its official website or other trusted≤≤☆​ download sources and foll•"ow the instructions to install it.÷‍®ε

l Configure environment variaφ♥εbles : Make sure that the Java pr×♦™↑ogram can call the Tesseract OCR engiΩ←ne. This usually requires adding the ×♣λTesseract installation path to t​∞he system's environme☆®nt variables.

l Create a Java project : Use a Java Integrated Developmen ←αt Environment (IDE) s$'uch as Eclipse, IntelliJ IDEA, e​ ≠tc. to create a new Java pφ'←εroject.

l Introduce Tesseract OCR's Java p£∑₽≤ackage library : Use dependency management to♠ ↓★ols such as Maven or Grad​★π€le to introduce Tesser¶¶&>act OCR's Java pa''<★ckage library, such as tess4j. This can☆γ÷  be achieved by adding↓ε∑ the corresponding dependencies in t&∑∏he project's pom∏•.xml or build.gradle file.

Write recognition code : Write code in a Java project↕∑£≤ to use the Tesseract OCR ÷±δlibrary to recognizeσ♥ ID card images.

Run and test : Run the Java progr¶↕£‌am, pass in the ID card im♦≠≠age path, and check

( 3 ) Functional expansion of ID card♥" recognition Java program

In addition to the basic ID card reco‌'$gnition function, the ≤δJava program can also achieve the ≠α∞following functional expansδ¶↑ion:

l Multi-card recognition : By integrating dif↔≈☆★ferent OCR engines or algorithms, it c≤&≈≈an realize the recogniΩ←tion of multiple car ®ds such as ID cards, soc✔±​♠ial security cards, driver맥9;s licenses, etc. This requires ≤∑×₩the use of the corresponding SDK dev¶←elopment kit and the←♥ correct calling of rela λ§ted functions accordin©φ™g to the documentation.

l Data parsing and storage♦÷ : Parse and process the iden£↔π≥tified ID card information, such₩   as extracting key information such as ≈ name, gender, date of birth, ×"address, ID card number, etc.,↔↑ and store it in the←™₩​ database or output it as a f← ile in a specified format. This c™✔an facilitate subsequent data analysis↔ε and utilization.

l User interface design : To improve user experience, you can &¥☆design a friendly user interface (UIλ•× ), such as providing function butto€λns and text boxes for im €♠age upload, recognitiγ₩€on result display, da€‍₹ta export, etc. This requires the u‍α™se of Java's GUI (graphε÷±ical user interface) library, such ±ε×as Swing or JavaFX.

l Exception handling and logging♣​ : During program operation, yo×✔u may encounter various e→<✔ xceptions, such as connectiλ↕↕on failure, card reading erro ×→r, etc. Therefore, you need to s★¶α et exception handling code around key o☆ '•perations and record relev ​ant log information for troubleshootφ∏♥δing and debugging.

l Security and privacy protec↑'ε★tion : When processing ID card i€↑δ₩nformation, relevant priv©πacy regulations must be followed ↔™to ensure data security↔÷. For example, sensitive infγ¥Ω↓ormation can be encrypted for storage↔ε and transmission to prevent data le✘•<akage. At the same time, user permissi≠♦≠÷on control and other issues should al↔δλso be considered in progra☆® ↕m design to ensure that only authorized¥ ∑ users can access an↕δ∏γd operate relevant data.

4. Data Security

To address the above ₩α •challenges, ID card §'←designs and uses inco ​∑rporate a variety of data secur∏‍ity features to ensure the security €β↑‌and integrity of personal informat™&€ ion.

( 1 ) Physical anti-counterfeiting techn≈λ→ology

n Unique ID : When the ID card is produc¥≥€•ed, a unique ID (such as UUID) is rando♥↑mly generated and saved in the in±↕ternal memory of the ±™±™ID card. This ID is unique and mat ≤→ches the record in the"↓λ↔ Ministry of Public φ$Ω♠Security database. When♣"¶ verifying the ID card, ¶$the authenticity can be easily ide±←ntified by comparing the in¥♥δternal ID with the Iφ☆ D in the database.

n Special materials : ID cards are made of →←∏£special materials, such  ∑≠'as anti-counterfeiting paper, a♥¥nti-counterfeiting ink, etφ→"c., to increase the difficul↕αty of forgery.

n Holographic anti-counterf​€eiting : Holographic anti-cou"​∞nterfeiting technology is applied ↓ to identity cards to verify authe★✔nticity through special optical effectΩ∏s.

( 2 ) Digital encryption technolo÷δgy

n Encrypted storage : In the database, encryption ☆φtechnology is used to store ID card infφ☆ormation, such as using encryption algβλorithms such as AES and RSA to •₩encrypt sensitive data. Thi​σs can prevent the data from being i÷α→↑llegally accessed or tamperedΩ  with during storage.

n Encrypted transmission : When ID card information is transm→‌φitted over the network<♥ , encryption protocols such as SSL/α<∑‍TLS are used to encrypt the data to e±≥nsure the security of←∏ the data during transmi€δssion.

( 3 ) Biometric technology

n Fingerprint recognition↓∑®∞ : embed a fingerprint rπσ↓ecognition module in the ID card t★→★★o verify the identity by comparing the ✔☆fingerprint information. This &<'→technology has high accuracy and rel£★≤♣iability and can effectively pre ☆αvent identity fraud.

n Facial recognition : Combined with artificial intelligenc‍♣e technology, facial recognition func‌βφtion is realized. By comparing the →★photo on the ID card with ©↑∞the facial image tak£α±★en on site, the authen ££♦ticity of the identity ∏→can be further verified.

( 4 ) Network verificati↔$on and remote authenti→σcation

n Online verification : Through the online platforms of auth‍¶oritative institutions such as the★ ✔ Ministry of Public Securit™ ♠¥y, online verification of ID card inf✘>‌ormation is achieved. When↔←₹ the ID card needs to be ve​↓σrified, the ID card iα☆nformation can be uploaded tα<o the online platform for comβε£"parison to confirm the a≠₹uthenticity of the identity.

n Remote authenticationΩδ♣≥ : Remote identity authenticatε£♦↑ion using biometrics or digital‍∏ certificates. This allows i≈™dentity verification to₽>∑ be completed without directly →₹presenting an ID card.

( 5 ) Intelligent authentication aε•₩nd risk detection

n OCR technology : OCR technology is used to automa​®tically identify and $ extract ID card information to imp→ ✘rove the efficiency and accuracy≥≤ of information collection. At the s₹≈ame time, combined with the risk dete₽≠ction algorithm, it can determine ™‌whether the uploaded I×$D card photo is a copy of the I¶​‌D card, a temporary ₹βσID card, a screen-shot ID card, or↓¥✔₽ a photoshopped ID card,←λ∏ and prompt the correspondin↕φ↑​g risk type.

n Big data analysis : Through big data analysis techn•★$ology, ID card informati​ δ↔on is deeply mined and analyzed. This c>∑αφan discover potential fraudα", identity fraud and other r↔β¶isks, and take corresponding p±↓λreventive measures.

( 6 ) Privacy protection an∞γd compliance

n Data minimization : When collecting, storing and processiφ®∏ng ID card information, follow t™§πΩhe principle of data minimization♥ φ, collect only necessary perso¶↕nal information, and strictl∑♣®↔y control data access​§©¥ and usage rights.

n Anonymization : When necessary, ID∑§≤γ card information will be Ω☆anonymized to protect personal privacγ☆×>y.

n Compliance review : In accordance with tΩ✔he requirements of relevant laws, regul∑★Ω♦ations and industry standards, con< ✘duct compliance review o♠>n the collection, storage, proce'∞α>ssing and transmission o¥♥π®f ID card information to ensurα<♠e the legality and stan∑ ♠φdardization of business opera¶₽tions.

( 7 ) Physical security measures

n Physical storage secu ♥"rity : Store ID card informaε• ☆tion in secure physic¶"$ al media, such as encrypted hard drives ₹, dedicated servers, etc., to preven®←​∞t data from being illegally acce♥≈‍ssed or leaked.

n Access control : Strict access control ♥¥♦>is implemented on the physical placeβ★s where ID card information ♦¥∑is stored, such as setting up a↓¶βαccess control systems, surveil×€→ lance cameras, etc., to ensuβ↓re that only authorized personne§Ω∏ l can enter.

5. Multi-application suppoδ♦ rt

The multi-application support of ID c‍ε₽ards means that they can play mu‍‌€ltiple functions in different sce≤&₹φnarios and fields to meet p♦ π≤eople's diverse needs. These func♦¥​tions are usually achieved by e§♠∑↓mbedding chips in ID card"☆↓s and applying special technologies<€. The multi-application support β↕→ of ID cards not only improves th ☆e convenience of use, but also further £€αλenhances its security and reliabili£>ty.

( 1 ) Specific function intro≤$duction

1. Identity Authenticati ≠♠>on

o Basic information storage : The ID card stores basic perso↔♠<∑nal information, such as name, gen¶£™✔der, date of birth, ethnicity, add♦<×₽ress, etc. This informש₹ation has been verified and Ω©βauthorized by relevant national depar↓≈≤tments and has certain legal¶→ £ effect.

o Biometric verification : Modern ID cards usually sλφ£•upport biometric technol≠↑•ogies such as fingerprint recognit≥≤ion and facial recognitio•≠♥n. By comparing persα→¥​onal biometric information with the inf₽ >∏ormation stored in tγ±he ID card, fast and accurate id≠★≠entity authentication can be<€ε  achieved.

2. Financial Services

o Bank card function : Some ID cards have‌←  been or are gradually © ₽being integrated wit∏←h bank cards. With the built-in chπ©ip or magnetic stripe, ID cards c↕∏≈→an be used for deposits, withdrawals‌∑<λ, transfers, and consum≠Ωption like bank cards.

o Electronic payment : Combined with mobile׶ payment technology, ID car'₹↔×ds can also support electronic pay¶₩ment functions. Users can bind♠≤÷& their ID cards to mobile payment∞✔★' platforms to achieve conven♦δient online and offline payments.

3. social Security

o Social security information inqui ↓‍✔ry : Through the ID card, u ∏sers can inquire about their p₹↑¥∞ersonal social security in≤¶formation, such as pension ∏ €insurance, medical insura₹★β↓nce, unemployment insurance, etc. Thiγ↑≈‍s helps users understand←±∑ their social security rig₽ hts and benefits.

o Medical insurance settlement : In some cities and reg&↔'ions, ID cards have been →₽integrated with medical insurance cards∞Ω‍. Users can directly use their→♠↑& ID cards to settle medical insurance©÷, without having to carry medical insuπ$‌σrance cards.

4. Transportation

o Public transportation card functi↓ on : Some ID cards also support✔✔‍ public transportati∏‌on card function, and users can useπ‍₩ their ID cards to take public ♣‌≥δtransportation such as buse♣€∏s and subways.

o Traffic violation process∏ ing : Through the ID card, user ↑s can check their personal traffic violσ÷✔ation records and hand≤♠<le related matters online.

5. Government Services

o Government information query : The ID card can be÷≈ used as the entrance to government ser≥‍±vices. Users can use the ID card ÷α←©to query various personal in ♠formation in the government field, ÷'✘such as taxation, indust±₩∑♦rial and commercial registrat•Ω¶ion, etc.

o Online government services : Combined with the gove×®rnment service platform, th©↔π☆e ID card can also support online go↓↑εvernment services, suc∑>h as online appointments, onlin♥♦e processing, etc. Thi±• ‍s helps to reduce users' waiting☆≈← time in queues and improve the efficie¥÷'‍ncy of government services.

6. Educational Services

o Student information inquiry : Through the ID card, students can cheφλ<ck their personal student informa™¥$tion, such as enrollment $₩time, school system, major, etc. This h✔₹♣elps students understand thei®"↔>r own learning situation.

o Library borrowing : Some school libraries have integβπ≠∏rated ID cards. Students can borrow€± books directly using theσπir ID cards without havα≈ing to apply for a l®↕ibrary card.

7. Other Services

o Access control management : In some places, such as office bui•γldings, residential area®₹∑∏s, etc., ID cards can be usedβ↓Ω‍ as access control cards. Usπ↔ers can enter and exitε♣∞ε these places with their ID card'φ∑s, which improves security and ♥★σconvenience.

o Membership card inteβ₽gration : Some businesses have launched meδ‌mbership card services that ₩≤are integrated with €≈★ID cards. Users can store thei ÷r personal membership card $γ<✔information on their ID cγ<®γards, making one card ♣α¥for multiple uses.

( 2 ) Technical implementati$≥•¶on and security assurance

l Technical Implementation

n Chip technology : Modern ID cards usually use c♦®Ω↕hip technology to store per∞↔ sonal information and ach☆ε£λieve multi-functional support.≈₩♦ The chip has the adva↑₽≠ntages of large storage capacity, ‌γfast reading and writing speed, an ∞d high security.

n Biometric technology : The application of biometri€$☆c technologies such as fingerp₹≥→₩rint recognition and facial recogni×Ω÷®tion has further improved the s₹≠×ecurity and convenience ₹ ♠≈of ID cards. These tec₹☆₩hnologies achieve ident"¶ity authentication by←β comparing personal biomeΩ‌$←tric information with theα™♥• information stored in the ID c>•ard.

n Mobile communication technology : Combined with mobile communica ♦ tion technology, ID cards can≠₩λ also realize functions su≈"ch as remote identity authenticat∑¥ion and electronic payment,↓↓ which provides users with a mor±₩γe convenient service experience.

l Safety and security

n Data encryption : Personal information ♦¥<in ID cards is usually encrypted to eσ☆™nsure data security. Even if the ID c₹®ard is lost or stolen, it is ♠★difficult for criminals to ob‌Ω<♣tain sensitive information.

n Multiple verification : When using an ID card to perform c←₩₩☆ertain operations, such as transferr®'$ ing money, spending, etc., multip∞§≤εle verifications are usually re€♠quired, such as password input, •≥< fingerprint recognition, e>← tc. This further improves '€β≠the security of the op​£>eration.

n Report loss and reissue : Once the ID card is β≈ ¶lost or stolen, the user can protec✘™t his or her personal information ✔✘and property security by reportiγ>αng the loss and reissuing it.

6. Network Communication

The network communication≠"∏ function of the ID card is mai÷γnly realized based on wireless communi←✔φcation technology. The ID ca©✘♣rd has an integrated wireless c←​♠ommunication module, which can com&♠βmunicate with external readi​★ng and writing devices to achieve γ‍•$data transmission and exchangeδ™♥. The wireless communic✔ ​≤ation module usually supp≥ orts multiple communicati¶≥¥♣on protocols, such as NFC (nearδ$ field communication), Bluetooth, ↕¶Wi-Fi, etc., to adapt to different app ★∑₩lication scenarios a÷‍λεnd needs.

( 1 ) Communication protocol

‌NFC (Near Field Commu↔₩ ∑nication)‌

NFC is a short-range high-frequency ♥​♦wireless communication technology th♣ at allows contactless point-to-poi≥€nt data transmission betwee™ ∞n electronic devices. IDδ∏ δ cards can communicate wireless¶→÷ly with NFC-enabled γ¶×©mobile phones, readers aεδ↓nd other devices thr≤>∑§ough the built-in NFC chip. NFC commu↑←≠Ωnication has the adv♦ ¶ antages of fast speed, high secur↔↑≈ity and low power consum≤₹✘​ption, making it very sui±λ∞φtable for network communication of ID §•cards.

Bluetooth

Bluetooth is a wireless com✔≥✘βmunication technology standarΩ< d used to interconnec♥₽t devices within a short d©"istance. Although Bluetooth may not≥¥✘" be as good as NFC inΩ>¶ transmission distan εce and speed, it has wider→↕" device compatibility. In the futur₽₩​≤e, as Bluetooth technology∏₽→ continues to develop and improve, ®↔ID cards may also support Bluetoo↑♥≠σth communication protocol₽α<s to achieve wider dev≥↔εαice connections and data transm‍Ωission.

‌Wi-Fi‌

Wi-Fi is a wireless Lβ∏✔AN technology based on the I£♣♠EEE 802.11 standard, with advan≠&tages such as long transmission  ≤distance, high speed and α £≈wide coverage. However, since ID cards ↓★ <are usually small in size and have l™α∞←imited power consumption, they do n₩ ot currently support the Wi-Fi communic" ‍ation protocol. However, witδ'h the continuous advancemenδ∑∑±t of technology and the continuous e →xpansion of ID card functions, the poss≤¶☆©ibility of ID cards supporting theε×>± Wi-Fi communication protocol in the fu©♦ture is gradually increasin¶ g.

( 2 ) Safety measures

Since the ID card sto∞‍res sensitive information such as ∞↑±the user's personal info¶™®rmation and biometric data, th₽$>e security of its network communicatio→÷∑'n function is of vital importance&© ★. In order to ensure the securityα♦≠ of the ID card's networγ×✔k communication function, ↕≤ >the following measur"‌∑πes need to be taken:

‌Encryption technology‌

During the network communicat♥ >γion process of the ID card, enc ≈πryption technology should be used to®>" encrypt the transmitted data. This ca∏'≠n effectively prevent the data from be"✔↑πing stolen or tampered wit♠€h during the transmission process and$≤α ensure the security and int↕βegrity of the data.

‌Authentication‌

Before conducting network comα£munication, both parties should ↑♦₹♦be authenticated. Only a☆∞&☆uthenticated legitimate us☆ ≤ers can transmit and exch♠£ange data. This can ef¥→→fectively prevent illegal users from γ↕₽∏impersonating legitimate us&✔↕ers to attack and da€↓↔mage.

‌Access Control‌

Access control management should ♥​λbe implemented for th <e data on the ID card. Only authori≈€zed users can access and 䮀modify the data on th™₽e ID card. This can prevent una₩>∞÷uthorized users from accessing sen‌↕β→sitive information or performing↓→ malicious operations₩•∑.

‌Security Audit‌

Conduct security audits and mo₩↔πnitoring on the network ←¶communication process of the ID card♠¶. Discover and handle abnormal behavi∞σ≥•ors and potential security thεβreats in a timely manner to ensur®≠e the security and stabiφ♣Ωlity of the network communication funct✘≈ion of the ID card.

7. Convenience

( 1 ) One card for multiple u䥩ses, integrated functions

The ID card not only has basic i™ γdentity authentication functions, bu₽↕γ"t also integrates a var✘₽iety of public service information, suc♥ ₩>h as social security, medical in≠  surance, etc., realizing the function ©↑of one card for multiple uses. Thi€​‌÷s means that users do not need to car§↕ry multiple cards, and only  ✔★need one ID card to meet multiple need✘♠s. This integrated desigε®αn greatly simplifies the user&σ↑#39;s daily carrying and use process an✘×€d improves convenienc¶Ωe.

( 2 ) Quick identity verifσ∑♥↔ication

The smart chip and biometric tech€♦>nology built into the ID c&♣π↑ard, such as fingerprint recogniti↓ on and facial recognitiλ♥>on, make the identity vδ>•‌erification process faster and more acc✘♣urate. Users only need to holdΩ→™" their ID card close to the cardφ®× reader or perform bi£ ometric recognition to com‌✘plete identity verification in ε&a short time. This fast identityσσ verification method not δ¥ε®only improves busine★✔ss processing efficiency, but als§≥®o reduces user waiting time.

( 3 ) Accessible cross-reg₹σΩ♦ional services

The ID card has a unifieδεd identification standard and lega£$l effect across the counα'δtry. No matter where the user is,"®$× he or she only needs to carry tγ>'πhe ID card to enjoy lo§&cal public services, such as♥δ↓ handling banking business, ap ≠ ↑plying for passports or vi★•sas, etc. This barrier-free ®★¶δcross-regional service pr₩¥★ovides great convenience for ↔♥users and reduces the cost of m ‌oving between different cities.

( 4 ) Convenience of electroni™™c ID cards

With the promotion and applicatiσ€on of electronic ID cards, userΩ↔☆>s can remotely read an​¶♥∑d verify their identity info"∞∑≤rmation through smart devices su©☆©ch as mobile phones. This ∞&ε<means that users can perform online id₹∏<entity authentication, onl₩&>ine payment and other operatio <ns without carrying physical ID ¶☆¥'cards. This electronic ID card ®÷not only improves the conve↓γnience of use, but also reduces₹<€♣ the risk of identity info∏♥₹rmation leakage.

( 5 ) Wide range of application sce®$Ωnarios

The convenience of ID cards i≤→↓s also reflected in their wide ranα≥☆ge of application scena↕☆Ω>rios. Whether in travel, accommodε‍αation, handling govern ∞ment affairs, or in banking, medical ca±↕↓re, education and other fie₹δlds, ID cards play an imp÷δortant role. For example, w≈↑♦hen taking an airplane or high-sp∏α≠‌eed rail, users only need to u←∞∏ se their ID cards to compl€'ete the ticket purchase and securi&&ty check process; when handling banki®₽♠ng business, ID cards can be use∑★§§d as an important basis for identit™↔y verification; in the medic​•§•al field, ID cards can be used for r≥λ∑♠egistration, medical ↕↓treatment and other processes.

( 6 ) Combination of smart↔• chips and IoT technology

With the development of Internet of ♠★×Things technology, ID cards ® ₽★can be seamlessly connΩ✔φected with smart devi∑↑£αces to achieve more intelligent  ≈∞services. For example, th<∏γrough smart chips and Internet of T¥∞ hings technology, ID cards can be asso§♥ciated with smart home device↓ ∏ s to achieve remote control and inλ"​telligent management. ₩™♣This intelligent application ♣Ω≥↔not only improves the q•$♣≤uality of life of users, b™≥±ut also promotes the innovation a♣♦ ↑nd development of ID card↓↓♣$ technology.

( 7 ) Balance between privacβ €y protection and convenieπ∑πnce

While pursuing convenienc ‌e, ID cards also focus β↔✔≈on protecting user priv‍"↔<acy. By adopting privacy protection m ≤easures such as encryption tec✔‌hnology and access control mechani★ § sms, ID cards can ensu••£re the security and £÷<privacy of user identity inform₹∏>→ation. This balanced design a↔ llows users to enjoy convenient¥‍≤  services while also being ∑$&≥able to protect their personal₹λλ information with con↑±≤≥fidence.

II. PC packaging manufacturing ‍​®₽process

The PC packaging process is an↔$"✘ important technology in the manu↓↕facture of electronic products. It i<"s mainly used to assemble el  φ£ectronic components and circuσ>its onto printed circuit ¥♣boards (PCBs) to form a comple↓×te circuit system. The following are ♦↑the main steps and details of the PC paγ★ckaging process:

1. Raw material preparation

l PCB material selection : Select appropriate PCB material •✔™according to the performance requiremen&​ts of the circuit and≈' the application environment, su✘≥ch as FR-4, CEM-1, CEM-3, etc.

l Copper foil selection : Choose the appropr​δ"iate copper foil according to the co™≤♠☆nductivity requirements of the circui'€t. Common ones are 1/2OZ, 1OZ, 2OZ, e÷σ∏<tc.

l Printing inks and electrolytes : Chemicals used to print circuits and ∑¥<etch copper foil.

2. Drawing design

l Design software selection : Choose appropriate PCB des£©₽σign software, such as Alti♠≈um Designer, PADS, Eagle, ₽±etc.

l Layout design : Carry out layout design according to✔< circuit function and size req¶±λuirements, and arrange the posi₩®tions of components reasonably.

l Circuit design : Draw a circuit diagram based on circ₹♥λuit functional requirements, an≤£'d determine the circuiα∞'∏t width, spacing, rou☆‍Ω♠ting method, etc.

l Component wiring : Component wiring is carried out​'σ according to the circuit diagram toδ☆≈λ ensure the stability and reliab£¥ility of signal transmission↔×‍.

3. Photolithography

l Generate photomask : Generate photomask according to ε‌ design drawings for makingγ©ε™ circuit patterns.

l Making a photosensitive plat €©e : Combine the photom♥βask and the photosensitive plΩ≠‍ate together through exposure✘☆ and development to form a ₽≈∏>photosensitive film pattern.

l Making a developing template : Transferring the p∑ ₽hotosensitive film p§ ♠ attern to the developing template throu ↕gh development to form a develop ±✔αing template pattern.

4. Etching

l Preparation of etching s→&>olution : Prepare the etching sol ≥ ution in a certain proportion​¶. Common ones include copper ferric §​"chloride, hydrogen peroxide, etc.•∑γ✘

l Etching process : The developing temσδ₽↕plate is combined wi₽☆©∞th the copper foil layer, immerseγ↔♣d in the etching solutio≠>→n, and the unnecessary cop<< per foil is removed thro>‍§ugh chemical reaction to form a circ∏≤αuit pattern.

l Cleaning and anti-corrosion : Clean the etched circu₩→it board to remove r₩" ≈esidual etching solution, and pe×£πrform anti-corrosion treatme​β₩nt to increase the durability÷₹↑♣ of the circuit board.

5. Plugins

l Component placement : According to the design drawings and ¶♣​BOM table, various electronic compβ≤onents are accurately plac¶&✔ed on the circuit board, incα×↑¶luding chips, capacitorε↓<s, resistors, etc.

l Soldering : Solder components to circuit boards t♦•o form a permanent c∞§£≈onnection. The weldin ↑g process requires attention to thλ$πe control of welding temperatur✔ ‍∏e, welding time and welding position ≈αto ensure welding quality and φ✔ δcircuit reliability.

6. Testing and debugging

l Electrical performance€‌ test : Use test instruments t∞♠≥o perform electrical performance tΩα→ests on circuit boards, i®φncluding tests on resistance, cur¶♠>rent, voltage and other para∑​ <meters.

l Functional test : By connecting the power π supply and test equipment, the v>♠>arious functions of the circuit board λ¥↓are tested to ensure the←© normal operation of the circuit↑Ω♣ board.

7. Packaging and Shipping∑↓©¥

l Cleaning and drying : Clean the qualified circui≤≤t boards to remove stains and residu÷↑es on the surface, and then dry them≥ ₽ .

l Packaging : Put the circuit bo☆ βard into an anti-static bag,  γ♠add shock-proof material, and then ₩φ↕&pack it into a paper box or wooden bo©™βx to ensure that it is not d↑♦λamaged during transportation.

l Shipping : The packaged circuit boards areε£ marked according to the cγ♦ustomer's order requiremπ>​'ents and handed over γ₽★Ωto the logistics company✔♦' for shipment.

See Annex 1 for details

III. Technology and details of blo₩∑ckchain workflow

Blockchain is a distributed databa↓'‌se technology that achieves data sto"γ✔ rage and transmission i£•n a decentralized manner. The followin÷∑αg are the main technolo←πgies and details of the blockcε₽ hain workflow:

1. Data record broadcast

l Sending node : The new data record is broadca₩≤₽st to the entire networβ÷k by the sending node.

l Receiving node : The receiving node verifies>↑ the received data record info↕φrmation, such as whether the record i₩♣Ω∞nformation is legal. After passing th≠φe verification, the data record wγ∏∞βill be included in a block.

2. Consensus Algorithm

l All network nodes : All receiving nodes in the entire net☆→↓>work execute consensusε↕♣​ algorithms on blocks, such as Pβ ±↔roof of Work (PoW), Proof of Stake (P☆ oS), etc.

l Block confirmation : After the block passes theβ$Ω§ consensus algorithm process, it is fo‍✘•rmally included in the blockc ≈δhain for storage, and all §γ↔©nodes in the network indicate that th≠¥β$ey accept the block. The method of exprδ© essing acceptance is to regard ™₽the random hash value of the∞<Ω£ block as the latest block hash valuε©≠e, and the production of ne∏≤≠w blocks will be extended based on the €<★blockchain.

3. Blockchain forks and solu₽↑™tions

l Node competition : If two nodes broadcast different vers¥☆λions of a new block at the sameπγ"​ time, other nodes may receive the ♠ block at different times.

l Work basis : The node will work on the basi§☆s of the block receive∏₽®d first, but will also keep β↕÷another chain in case the latt≥♦er becomes the longer cβ✘​hain.

l Consensus algorithm operation : Breaking the deadlock requires​  further operation of the consens←✘÷♥us algorithm. When one of the ch​Ωains is confirmed to be th≈‌₹e longer one, the noλ¶♠des working on the other branch ch​₹≤γain will switch camp€™Ωs and start working on the lo★γnger chain.

4. Data security and i&∑↔≠mmutability

l Timestamp : Blockchain not only focus♥ ∏es on the content in the data bl♣€≈γock, but also on the data block it₹γself. The timestamp links the content oβ§f the data block with the data block it ←∑☆self, forming a new structure for theλ←​ data block. This new st☆>ructure connects each b<£γlock in an orderly manner thro≈σ₩&ugh the timeline, forming a chain o±​←∏f blocks.

l Data encryption signature ™λ₩mechanism : The private key is the key to p'£rove personal ownersh≤λip. A digital signature₩♠ proves that someone has the right→&£₩ to consume digital cur•♦™rency from a specific wallet. ↔±↑∑At the same time, the hash algo∞↑rithm is used to tran÷★sform input of any len®≈♣γgth into output of fixed↔✔π♥ length, which is irreversγ←ible.

l Consensus algorithm : The consensus algorithm is the basis₹₩φ for nodes in the blockchain to keep ←•block data consistent and accurate. T↑★he consensus algorithm → ensures that the acc  eptance and storage of blocks by nodes€π↑↓ across the network are ‌♠λconsistent.

5. Blockchain application exampε₹​le: Java-based blockchain digita§<&£l identity authenticatioφ ✘®n

The following is a simple example o÷♦✔>f blockchain digital identity a ♥uthentication based on★≤↔∑ Java:

a. Smart contract writing

On the Ethereum blockchain, sπ÷mart contracts are a key part✘↔ of implementing blockchain applicationγσ& logic. The following is a simp±&le smart contract exa∑≠βλmple that manages theε&§ registration and ver∑€​≈ification of user identity iα$±¥nformation:

package cn.juwatech.bloc<≠kchain;

import org.web3j.abi.datatypes.Address;α≠≈

import org.web3j.abi.datatypes.& γ÷generated.Uint256;

import org.web3j.abi.©δ∑™datatypes.Utf8String∑≤§;

import org.web3j.protocol.Web3j;

import org.web3j.protocol.core.Re≥≠‍moteCall;

import org.web3j.protocol.core.meth♥σ×ods.response.TransactionRece€♦↔ipt;

import java.math.BigInte₩♠ δger;

public class IdentityContr♣&©act {

private final Web3j web3j;

    privδπ★ate final String contr♥®↕actAddress;

   &nb↑$♣λsp;public IdentityCo$‍×★ntract(Web3j web3j, String contract★‍§Address) {

     &nb≠™₹>sp;  this.w≥©≥βeb3j = web3j;

     &δ§✘→nbsp;  thi¶&£≥s.contractAddress = con÷♣¥&tractAddress;

    }

    pu♠α♣blic RemoteCall registerIdentity(String userId,©​ String publicKey) {

    &✔ ;   &<↓nbsp;Identity identity≥γ®∏ = Identity.deploy(web3j←★, new Utf8String(userId↕¥), new Utf8String(publicKey)).sendAsynε>c().join();

    &nbsε∏p;   return identity.r•♣egister();

   &nb♠>sp;}

    £✘;public RemoteCall verifyIdentity(String userId, S ≈↓tring publicKey) {

   &nb≈ "αsp;    I™←→¥dentity identity = Identity↓☆↑.load(contractAddress€♥, web3j, new Utf8Strin≠©g(userId), new Utf8String(publi∑×cKey), BigInteger.ZERO);

    ™₩π;    β©₹φ;return identity.verify();

    }

    pub☆♥ lic static class Identity {

     &nb ≠€ sp;  public static RemoteCall<§≠₽ deploy(Web3j web3j, Utf8String userId$±', Utf8String publicKey) φ₩​☆{

     &n& βbsp;     &nbs→>p;// Deploy smart co"♥"πntract

      ↓∑→  }

      &nb←♠≈sp; public RemoteCall register() {

    &nbs₽σp;   &nbsφ γ&p;   //✔£Ωδ Register identity

     ₽σ;   }

      &¥¥↓nbsp; public RemoteCall verify() {

     &n₩×↑↑bsp;     &nb δ sp;// Verify identity

      &nb≈≤sp; }

      ®↕¥;  public static Id‌¶±entity load(String contra÷✔ $ctAddress, Web3j web3j, Utf8Stri βng userId, Utf8String publicKeγ♥y, BigInteger gasPrice) {

   &nσ÷Ω✔bsp;    ε∏;   &✘‍$nbsp;// Load existing contract

     →∞;    }

    }

}

b. Java backend service

In addition to the smart contract, a Jaπ>va backend service is also req™‌¥εuired to integrate with the fron‌∞✔βtend or other applications and han¶☆dle identity authentication reques☆λ£δts initiated by users:

package cn.juwatech.blockch σφσain;

import org.springframework.web.### Ja‍βva backend services (​←continued)

#### Backend service example

The following is an examp•↓δle of a Spring Boot-based Java backe←σnd service that handles authentica§£&tion requests and interacts with €ε÷®smart contracts on the Ethereum blockch&δ↔εain:

```Java

package cn.juwatech.bloc↓§★₹kchain.service;

import cn.juwatech.b✘→♦lockchain.IdentityContr&®act;

import org.springframework.beans.f‍>‌Ωactory.annotation.Autowired;

import org.springframe∏÷€±work.stereotype.Service;

import org.springframework.web.bind.ann'₩Ωotation.*;

import org.web3j.protocol.We♥≈b3j;

import org.web3j.protoco¶÷☆l.core.DefaultBlockParameterName;

import org.web3j.protocol.core.methoε♠<¶ds.response.TransactionReceipt;

import org.web3j.protocol.http.HttpSer¶<vice;

import org.web3j.tx.ClientTransactioα™nManager;

import org.web3j.tx.TransactionM©σ§anager;

import org.web3j.tx.gas.Contracδε₩tGasProvider;

import org.web3j.tx.gas.Defa↓✘φultGasProvider;

import java.math.BigInteger;<♣ 

@Service

@RestController

@RequestMapping("/identity")

public class IdentityService {

    @Au•÷towired

   &nb≥✔φsp;private Web3j web3j;

private final String contractAdd ×​₹ress = "YOUR_CONTRACT_ADDRESS";βσ£  // Replace with your smart contract ad​÷✔dress

private final String priva¥₽™¶teKey = "YOUR_PRIVATE_KEY"$×<; // Replace with your private key

private final TransactionManager tra"☆<∑nsactionManager;

private final IdentityContract ✔∏↓<identityContract;

public IdentityServi ®↕←ce() {

this.web3j = Web3j.build(new HttpServ✘∑ ice("YOUR_INFURA_OR_ETHEREUM_NODE_®↕URL")); // Replace wiπφth your Infura or Et™>¥hereum node URL

this.transactionMana♥÷ger = new ClientTransaction₩<®₹Manager(this.web3j, this.prε₽ivateKey);

this.identityContract = new IdentityCo•£ntract(this.web3j, this.contractAdd₹≠&πress);

}

@PostMapping("/register÷φ")

public TransactionReceipt registerI∏₹✘'dentity(@RequestParam String uφα♠βserId, @RequestParam Strin¥₹↑'g publicKey) throws Except↕∞Ω↓ion {

return identityContract.registerIdentit★Ω y(userId, publicKey).send();

}

@GetMapping("/verify")

public Boolean verifyIdeεφσntity(@RequestParam S↔≠tring userId, @RequestParam String publ±δicKey) throws Exception {

// Note: The verify method here may req÷≥uire you to adjust i✔÷t according to the actua☆∞l implementation of the smart contract←&→

// Here we assume that the verify •®method of the smart contract≥π& returns a Boolean valu ←e

// But in reality, smart‌α contracts usually do not return Bo↕☆≥olean values directly, but return ↑★‍ a transaction receipt"≠€₩ or other indicator in∏≥∑dicating that the operation was succes&♣∏‍sful

// Therefore, the code here ≈→βφmay need to be modified accordinσδ≈£g to the actual situati↑≥✔±on

// For example, you may need to ch‌'eck if the transaction was su¶ ÷♣ccessful and query the blockchain to g'÷←et the latest smart conε≤tract status

// Temporarily return a ₩∏₩'false boolean value as a↑‌•n example

// In actual implementation, y∞£™ou need to process according to t★∞he return result of the smart co♥✘ntract

return true; // Here we shou∏γ×εld judge whether the verifi&✔Ωcation is successful based on the ₽≠σ∏return result of the smπ"β☆art contract

}

}

Notice :

1. The verifyIdentity method above±↕ ↑ is just a placeholder. In✘Ω₽δ actual implementation↕≤₽, you need to handle it according to th±β"e return result of the smart contract. '®Smart contracts usually do not dir€↔★♦ectly return a Boolean value to ind₽•₽<icate whether the verificatio§"↕€n is successful, but instea♠¥d return a transaction r↓∑¶¶eceipt (TransactionReceipt) or othα →er identifier indicati£± ♠ng that the operation was su ♣≈©ccessful. You need to checkφ‍↔ whether the transaction isφ<• successful, and may need t∏&€φo query the blockchain to obtai✔÷n the latest smart cont€φλract status to determine whether₹♠" the verification is successful.

2. In an actual production environmen‍>€t, please make sure your private keys•" and smart contract addresse♠∞↑s are safe and do not hardcode them ←∏in the code. You can use en©>vironment variables, configuration fil•♦≈<es, or encrypted storage to manage the✘♣se sensitive information.

3. You also need to conγ‌≈αfigure other parts of₽εσ₩ the Spring Boot applicatλ ion, such as database connections, ↕α$security settings, etc., which ar‌✔€₩e not shown in this eε≤xample.

4. During actual deployment, pleas✘÷$e ensure that the net♠₩↑§work connection betweenα¥ ↓ your backend service and the‍γ↔ Ethereum node is stable a×±nd secure.

5. Please note that thi↑ •s sample code is written to illustrat≤✘λ÷e how to write a Java bacε★kend service that int§'↑eracts with the bloc←‍♦£kchain, and it does not include all$↕<✘ possible error handling and exception★♣♦ handling logic. In actual applicatio✘&φ¥ns, you need to add appropriate error ‍ handling and exception handling logic ​→‌¥according to specific needs.