# PUBLIC KEY AND PRIVATE KEY: HOW THEY WORK AND DIFFER — TECHSLANG

At dnth.vn we often find ourselves explaining khổng lồ our customers the concepts of how public & private keys work. We thought it would be helpful khổng lồ discuss what these keys are, what they aren’t, and how they work.The blog below provides a general overview on public và private key pairs rather than an architectural overview of dnth.vn. For a detailed understanding of dnth.vn’s public-private key architecture, please kiểm tra out our architectural whitepaper.

Bạn đang xem: Public key and private key: how they work and differ — techslang

## How public và private key encryption works

Public & private keys khung the basis for public key cryptography , also known as asymmetric cryptography. In public key cryptography, every public key matches lớn only one private key. Together, they are used lớn encrypt và decrypt messages. If you encode a message using a person’s public key, they can only decode it using their matching private key.

Public & private keys: an exampleBob wants to skết thúc Alice an encrypted gmail. To do this, Bob takes Alice’s public key và encrypts his message to her. Then, when Alice receives the message, she takes the private key that is known only khổng lồ her in order khổng lồ decrypt the message from Bob.Although attackers might try to compromise the hệ thống & read the message, they will be unable lớn because they lack the private key to lớn decrypt the message. Only Alice will be able to lớn decrypt the message as she is the only one with the private key. And, when Alice wants lớn reply, she simply repeats the process, encrypting her message lớn Bob using Bob’s public key.

**More on how public & private keys are used: ***Whitepaper:* dnth.vn Security và Design*Article:* End-to-end encryptionThe difference between public and private keysPublic keys have sầu been described by some as being like a business’ address on the website – it’s public & anyone can look it up & tóm tắt it widely. In asymmetric encryption, public keys can be shared with everyone in the system. Once the sender has the public key, he uses it to lớn encrypt his message.Each public key comes paired with a unique private key. Think of a private key as akin to the key khổng lồ the front door of a business where only you have a copy. This defines one of the main differences between the two types of keys. The private key ensures only you can get through the front door. In the case of encrypted messages, you use this private key lớn decrypt messages

Together, these keys help lớn ensure the security of the exchanged data. A message encrypted with the public key cannot be decrypted without using the corresponding private key.

Generating public and private keysThe public and private key are not really keys but rather are really large prime numbers that are mathematically related to one another. Being related in this case means that whatever is encrypted by the public key can only be decrypted by the related private key.A person cannot guess the private key based on knowing the public key. Because of this, a public key can be freely shared. The private key however belongs to only one person.There are several well-known mathematical algorithms that are used to lớn produce the public và private key. Some well-respected algorithms include:

*Rivest-Shamir-Adelman (RSA)*– Oldest of the public-private key cryptography systems. Frequently used to lớn transmit shared keys for symmetric key cryptography

*Digital Signature Standard (DSS)*– a Federal Information Processing Standard specifying the algorithms that can be used to lớn generate digital signatures used by NIST

**Summary Public key cryptography**Public key cryptography provides the basis for securely sending & receiving messages with anyone whose public key you can access.

Xem thêm: Cách Đăng Ký Sms Plus - Dịch Vụ Sms Plus Viettel Là Gì

*Public keys enable:*Users to lớn encrypt a message to other individuals on the systemYou can confirm a signature signed by someone’s private key

*Private keys enable:*

## Public-private key encryption: Real world examples

Digital signaturesPublic và private keys can also be used khổng lồ create a digital signature. A digital signature assures that the person sending the message is who they clayên ổn to be.Typically, we use the recipient’s public key to lớn encrypt the data & the recipient then uses their private key khổng lồ decrypt the data. However, using the scheme of digital signatures, there’s no way lớn authenticate the source of the message. Mike could get a hold of Alice’s public key (since it’s public) & pretkết thúc that Bob is the person sending a message khổng lồ Alice.To create a digital signature, Bob digitally signs his email lớn Alice using his private key. When Alice receives the message from Bob, she can verify the digital signature on the message came from Bob by using his public key. As the digital signature uses Bob’s private key, Bob is the only person who could create the signature.dnth.vn’s method for securing messages is a bit more complex than the example provided above. However, the example provides a good general overview for how asymmetric encryption works.

Diffie-Helman key exchangeThe Diffie Hellman key exchange demonstrates an example of how users can securely exchange cryptographic keys over a public channel.In the past, secure encrypted communication required that the individuals first exchange keys by a secure means such as paper key lists transported by a trusted courier. The Diffie–Hellman key exchange method allows two parties that have no prior knowledge of each other khổng lồ jointly establish a shared secret key over an insecure channel.dnth.vn uses the Diffie Hellman key exchange khổng lồ enable Web dnth.vn. Web dnth.vn is a browser based end-to-kết thúc encrypted gmail service that allows users to lớn easily access their secure tin nhắn tài khoản on the website without any software tải về or any passwords lớn rethành viên.Here’s a đoạn Clip lớn explain how this works:

## Business benefits of public private key encryption

By using a public and private key for encryption and decryption, recipients can be confident that the data is what the sender says it is. The recipient is assured of the confidentiality, integrity & authentiđô thị of the data.**Confidentiality **is ensured because the content that is secured with the public key can only be decrypted with the private key. This ensures that only the intended recipient can ever Đánh Giá the contents**Integrity** is ensured because part of the decryption process requires checking that the received message matches the sent message. This ensures that the message has not been changed in between.**Authentiđô thị **is ensured because each message sent by Alice to Bob is also signed by Alice’s private key. The only way to decrypt Alice’s private key is with her public key, which Bob can access. By signing the message with her private key, Alice ensures the authenticity of the message and shows that it really did come from her.

Public and private key pairs khung the basis for very strong encryption & data security. If you are interested in reading more about public and private keys, take a look at the following articles: