What is a Private Key?
Private key is a key known only to its owner and kept secret. It is usually used for:
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Encrypting and decrypting data: Data encrypted with the public key can only be decrypted with the matching private key.
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Authentication: It is used to create a digital signature, which can be verified with the public key.
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In SSL/TLS certificates: It is used to verify the identity of web servers and set up a secure connection.
Public Key vs Private Key
| Property | Public Key | Private Key |
|---|---|---|
| Sharing | Can be shared with anyone | Known only to the owner |
| Use | Encryption, verification | Decryption, signing |
| Security Risk | Low | High (must be kept secret) |
📁 What Does a Private Key File Look Like?
It usually has the .key extension and starts like this:
-----BEGIN PRIVATE KEY-----
MIIEvQIBADANBgkqhkiG9w0BA...
-----END PRIVATE KEY-----
This file must be stored on your server or in a secure place. It must never be shared with third parties.
⚠️ Security Warning
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Never share your private key with anyone.
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Encrypt it and keep it in a safe place.
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If you lose it, your certificate becomes invalid and you will need to create a new one.
