Under normal circumstances, unplugging the network cable, turning off WIFI, and physically isolating the cold wallet from the network is safe.

　　But if the funds in the cold wallet are too much, enough to affect your life, it is better to be more careful.

　　Generally, we use a separate computer, mobile phone, or bootable USB drive to make a cold wallet.

　　The login password after the Linux or Windows startup is just a preliminary protection. Once the cold wallet is obtained by the hacker, they can bypass the login password to modify files.

　　Once the files in the cold wallet have been maliciously modified, and the user is unaware of it, continuing to use the modified cold wallet may pose a risk of losing coins.

　　If the operating system or wallet program used to create the cold wallet itself has been modified, it is even less secure.

　　Potential security risks of offline cold wallets:

　　1. Modify the random number generator of the operating system.

　　The generation of wallet addresses and the signing of transactions depend on random numbers. Once the random number generator of the operating system is modified, the generated random numbers have a specific pattern, and even offline is not safe.

　　a. The random number does not have enough entropy, and the wallet address is easily brute-forced.

　　b. If the hacker knows the random number used for transaction signing, the private key can be deduced through mathematical formulas.

　　c. If the same random number is used for the same address in two transaction signatures, the private key can be deduced through mathematical formulas. There are examples of this in the existing blockchain.

　　2. Modify wallet programs

　　Most wallet programs are open source, and hackers can easily compile a malicious version. Once there is an opportunity, they may replace the genuine version without the user’s knowledge.

　　Offline cold wallets are usually used to sign payment transactions. Malicious wallet programs may tamper with the signing step, such as: changing the address to which the balance is sent to the hacker’s address before signing.

　　This malicious modification may only target large wallet addresses, that is, for small wallet addresses, everything is normal.

　　3. Leakage of ultrasonic information.

　　Under normal circumstances, we believe that information is transmitted through Ethernet, WIFI, and Bluetooth. On offline computers or mobile phones, hacker programs may also send information by generating ultrasonic sounds (high-frequency sounds).

　　High-frequency sounds above 20KHz are inaudible to most people, but can be heard by dogs, bats, and hackers’ recording equipment.

　　4. Malicious USB firmware attack

　　USB devices include flash drives, keyboards, mice, and others. If the USB communication firmware is overwritten, it may be possible to launch an attack on the system. For example, simulating USB keyboard input, modifying files, and so on.

　　5. Do not use unreliable chargers for cold wallets made from tablets and smartphones.

　　Most mobile phone chargers are USB ports, which is similar to the fourth point. It is just that because the charger is used too frequently, it is easy to be overlooked. At the same time, people often have the habit of borrowing chargers and using public chargers. Maliciously modified USB chargers may modify files or inject programs.

　　Suggestion:

　　1. When making a cold wallet operating system and wallet program, be sure to check carefully to ensure that it comes from the official website and has not been modified.

　　2. Do not use unreliable USB devices including USB flash drives, keyboards, mice, and chargers.

　　3. You need to have a way to identify whether your wallet has been secretly modified. (During a bath or on vacation)

　　Locking the cold wallet in a safe deposit box is safer, and sealing the USB wallet with an envelope and signing at the sealed place is also a good method.

　　Cold wallets, also known as offline wallets, include hardware wallets, paper wallets, and brain wallets. It can be通俗 understood as wallets used in environments without network connection. Hardware wallets are not necessarily 100% cold wallets. The cold wallets we are talking about refer to the fact that the private key and signature actions are always offline, and this is used to define them as cold wallets. Therefore, cold wallets can also be formed in hardware form, or as a software.

　　Therefore, many wallet apps support the operation of cold and hot separation.

　　There are two concepts of electronic wallets: one is pure software, mainly used for online consumption and account management, and this type of software is usually connected to bank accounts or credit card accounts. The other is a smart stored-value card for small payments, where the cardholder pre-deposits a certain amount in the card, and the transaction amount is directly deducted from the stored-value account during the transaction.

　　Electronic wallets are a commonly used payment tool for customers in e-commerce shopping activities, and a new type of wallet commonly used for small purchases or the purchase of small items. Shopping with an electronic wallet usually requires the use of the electronic wallet service system. The software of electronic wallets in e-commerce activities is usually provided for free, and can be used directly with the electronic wallet software connected to the e-commerce system server of their bank account, or it can be downloaded from the Internet using various encryption methods to use the electronic wallet software on the Internet. Currently, there are two major electronic wallet service systems in the world: VISAcash and Mondex, and other electronic wallet service systems include MasterCardcash, EuroPay’s Clip, and Belgium’s Proton, etc.

　　Customers who use electronic wallets usually have accounts in banks. When using an electronic wallet, the relevant application software is installed on the e-commerce server, and the electronic wallet service system can be used to input various electronic currencies or data on electronic financial cards. When payment is made, if the customer wants to pay with an electronic credit card, such as using Visa or MasterCard for payment, the customer can complete the payment by simply clicking on the corresponding item (or icon). This electronic payment method is often referred to as a one-click or shock payment method.

　　In the electronic wallet, only electronic currency can be completely stored, that is, to load electronic cash, electronic coins, secure coins, electronic credit cards, online currency, lottery and How to find it, etc. These electronic payment tools can all support one-click payment methods.

　　In the e-commerce service system, there is a functional module for the management of electronic currency and electronic wallet, known as the electronic wallet manager. Customers can use it to change secret passwords or secret methods, and use it to view the electronic currency accounts, lists, and data on their bank accounts. The e-commerce service system also has an electronic transaction recorder. Customers can understand what items they have purchased, how much they have purchased, and can also print out the query results by querying the recorder.

　　Although the use of electronic wallets often starts from a centralized city or industry, if different industries and regions develop their own electronic wallets, universality becomes an important issue. The universality brought by unified standards enables different electronic wallet acceptance terminals to be shared at a low cost, which is an important premise for the cross-industry and cross-regional development of electronic wallets. In terms of China, the People’s Bank of China’s financial IC card standard has established the standards for electronic wallets and electronic deposit books in China, laying the foundation for the unified development of electronic wallets in our country. Currently, this standard has not established a non-contact standard, which means that this standard cannot enter the largest application field of electronic wallets – transportation, and therefore needs to be further improved.

　　At present, electronic wallets in China are roughly divided into two categories: industry electronic wallets (or quasi-electronic wallets) evolved from industry cards and general electronic wallets issued by banks. Due to historical and existing system reasons, the public transport industry is the most developed field of industry cards and the cradle of industry electronic wallets.
online casino tutorial and The most exciting gameplay
　　Currently, various large and medium-sized cities in China are implementing bus card projects, with different standards and implementation methods. The development of the bus card industry in Shanghai and Guangzhou is relatively rapid, mainly due to the large population base, which can bring considerable profit to the project with its transaction volume and accumulated capital. According to incomplete statistics, the number of bus

　　Another type of industry electronic wallet that can be compared with public transport cards is the catering cards and commercial cards issued by various regions for shopping in supermarkets and department stores. This type of card is generally used for official expenses or as welfare provided by companies to their employees, and has special marketing advantages that other industry cards cannot match.sports betting platform and The latest website

　　Abroad, general electronic wallets are regulated by financial institutions, while China lacks corresponding legal regulations for electronic wallets. Therefore, various industry cards entering the small payment field have no regulations to follow as general electronic wallets, and can only be gradually渗透. Shanghai’s public transport card has been used for paying water, electricity, gas fees, and can also be used for shopping in some supermarkets. The same is true for catering cards and commercial cards.

　　In addition to industry cards, the IC cards issued by each bank according to the People’s Bank of China’s financial IC card specifications are basically universal electronic wallets that meet the PBOC standard. For example, the Peony Traffic Card in Beijing, the Petrochemical Oil Card issued by the Industrial and Commercial Bank of China, etc.

　　Although bank electronic wallets have appeared since the 1990s, they have not been widely promoted in practical applications. So far, the issuance of pure bank electronic wallets (excluding co-branded cards) has only reached over 2 million.

　　Considering the overall income of commercial banks, electronic wallets, like debit cards, can absorb deposits, and do not need to pay interest, nor occupy the bank’s background system and communication resources, making it a card type with significant income. However, the promotion of electronic wallets still faces certain difficulties. Firstly, just like the United States, communication costs in China are much lower than in Europe, making the offline transaction cost advantage of electronic wallets negligible. In the small payment field where bank debit and credit cards can enter, besides the advantage of transaction speed, electronic wallets have little to offer in other aspects. Secondly, the small payment field with high requirements for transaction speed mainly includes highways, parking lots, subways, buses, taxis, and fast-food restaurants, where contactless cards are more practical. However, as of now, the bank’s electronic wallet does not have a non-contact standard, so its application in some small payment fields is limited. Additionally, in terms of marketing methods, one of the important reasons why industry cards can be promoted is that they can issue commercial invoices, forming the main sales channel for value-added cards through group purchases. However, bank electronic wallets do not have this marketing channel for group purchases. Therefore, banks are very cautious about investing in purely payment-oriented bank electronic wallets.

　　Of course, due to the need for inter-industry competition, some industries have also begun to open their own business platforms, fully utilizing the payment function advantages of financial electronic wallets to attract more consumers.

　　Electronic wallets are widely used, bringing a lot of convenience to people!!

　　Binance Exchange

　　20 million users have joined Binance Exchange

　　Download immediately