Private Key

A private key, also known as a secret key, is a variable in cryptography that is used to decrypt and sometimes encrypt messages. Private keys are used with public keys in asymmetric encryption, and they are used by themselves in symmetric encryption. They are known only to the key’s generator and play an important role in cryptocurrencies. The use of private keys enhances data and identity security at scale.

Public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them. Moreover, it is virtually impossible to deduce the private key, even if you know the public key.

Symmetric encryption

Symmetric encryption, also known as private key encryption, is a type of encryption where the same private key is used to encrypt plaintext and decrypt ciphertext. A private key is typically a long, randomly-generated number that is difficult to guess. The keys represent a shared secret between two or more parties that is used to maintain private information. However, both parties have access to the mutual secret key, making it less secure in comparison to asymmetric encryption.

Symmetric encryption can use either stream ciphers or block ciphers. A stream cipher applies a private key and algorithm one bit of data at a time, whereas a block cipher applies the key and algorithm to a block of data simultaneously. Most processes use symmetric encryption to encrypt data transmissions and asymmetric encryption to encrypt and exchange the private key.

Private keys in cryptocurrency

A private key allows users to access their cryptocurrency and is an essential part of bitcoin and altcoin. Cryptocurrency refers to digital money that can be purchased, transferred, and/or sold securely using cryptography, which encrypts and protects the data used to help identify and track cryptocurrency transactions.

In cryptocurrency, users are given a public address and a private key to send and receive digital coins or tokens. The public address houses funds while the unique private key grants access to those funds. A private cryptocurrency key is typically depicted as a series of alphanumeric characters. A digital wallet can store a user’s private key. If a user loses their private key, they can no longer access the funds to spend, withdraw, or transfer coins.

Private key vs. public key

In asymmetric cryptography, the main difference between a public and private key is that a public key encrypts while a private key decrypts.

Abby Braden
Abby Braden is an award-winning writer and editor for websites such as,, and, where she covers technology trends and enterprise and SMB project management platforms. When she’s not writing about technology, she enjoys giving too many treats to her dog and coaching part-time at her local gym.

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