Hashing and Encryption: What You Need to Know
- Online threats
Contents
What is Hashing?
Hashing is a one-way function that converts data of any length into a fixed-length output, known as a hash value or digest. The characteristics of a hash function are as follows:
① The same input always produces the same output.
② Different inputs are unlikely to produce the same output.
③ It is not possible to reverse-engineer the input from the output.
The primary purpose of hashing is to verify data integrity, meaning to check whether the data has been tampered with or corrupted. For example, when you download a file, you can compare its hash value with the official hash value provided. If they match, the file is likely intact. Commonly used hashing algorithms include MD5, SHA-1, SHA-256, etc.
What is Encryption?
Encryption is a two-way function that converts data into another form, known as ciphertext, to prevent unauthorized access or reading. The characteristics of an encryption function are as follows:
① It requires a key to perform both encryption and decryption.
② The same input can produce different outputs, depending on the key.
③ It is possible to reverse-engineer the input from the output and key.
The main purpose of encryption is to protect data confidentiality, meaning to prevent data from being stolen or leaked. For example, when you send an email, you can use encryption to protect the content from being intercepted or viewed by third parties. Commonly used encryption algorithms include AES, RSA, DES, etc.
Hashing and encryption are two different data security techniques that can be used to protect information from tampering or disclosure. Hashing is an algorithm that converts data of any length into a fixed-length output, while encryption transforms data into another format that can only be accessed or decrypted by someone with the correct key. Both methods have their own applications and advantages, and below are some common examples.
Examples of Hashing Usage
① Password Verification
When users register or log in to a website, their passwords are not stored in plain text in the database. Instead, they are hashed and stored. This way, even if the database is compromised, the original passwords cannot be recovered, ensuring user privacy and security.
② Digital Signatures
Digital signatures are used to verify the source and integrity of files or messages. They combine hashing and encryption. The sender hashes the file or message, then encrypts the hash value with their private key to generate a digital signature. The receiver hashes the received data, decrypts the signature using the sender's public key, and verifies if the hashes match, ensuring the authenticity of the file or message.
③ Blockchain
Blockchain is a distributed and tamper-proof database composed of interconnected blocks. Each block contains the hash value of the previous block, ensuring data integrity. Any modification to the content of a block would change its hash value and be detected and rejected by other nodes in the network. Blockchain utilizes the irreversibility and collision resistance of hash algorithms to achieve decentralization and security.
Examples of Encryption Usage
① Communication
Confidentiality When two or more parties need to exchange sensitive information, they can use encryption to ensure that the communication content remains confidential and cannot be intercepted by third parties. For instance, when accessing a website using the HTTPS protocol, the communication between you and the website is encrypted, and only you and the website can decrypt and read it. Even if someone intercepts the data packets you send or receive, they cannot decipher what web pages you browse or what information you input.
② Data Backup
When you need to store important or private data in the cloud or external devices, encryption can be used to protect the data from unauthorized access or modifications. For example, tools like BitLocker can encrypt entire hard drives or USB drives, allowing access only with the correct password. Alternatively, tools like 7-Zip can compress and encrypt files or folders, which can only be opened by providing the correct password.
③ Cryptocurrencies
Cryptocurrencies are virtual currencies based on encryption and blockchain technologies. They have no central issuing or managing authority but are maintained and verified by participants on the network. For instance, Bitcoin uses public-key cryptography and digital signatures to ensure transaction validity and security. Each user has a pair of public and private keys, with the public key used to receive Bitcoins and the private key used to send Bitcoins. Transactions are signed with the sender's private key and then broadcasted to the network. Other nodes verify the transaction using the sender's public key. If the verification is successful, the transaction is recorded on the blockchain.
④ Avoiding Cybercrimes
Using encryption can effectively protect you from cybercriminals, especially on public Wi-Fi networks, which are commonly targeted by hackers. To enhance security, MetroVPN encrypts users' internet traffic, ensuring data protection. Therefore, using a MetroVPN provides an additional layer of security when connecting to public Wi-Fi, safeguarding your data from illegal intrusion.
Hashing and encryption are different data processing methods, each of which helps to protect the security and integrity of data. Hash converts data into fixed length output, which is mainly used for Data integrity verification, while encryption converts data into another form to ensure data confidentiality and prevent unauthorized access. Both methods have different applications and are crucial for ensuring data security in different scenarios.
