What is a private key?

A private key is a sensitive piece of cryptographic information that is used in asymmetric encryption systems, such as RSA or ECC (Elliptic Curve Cryptography). In these systems, a pair of keys is used: a public key and a private key.

The private key is kept secret and is known only to the owner. It's used to decrypt data that has been encrypted with its corresponding public key. Additionally, the private key is used to sign digital messages, ensuring that they came from the owner of the private key and have not been tampered with.

On this page, you can find guides on creating private keys with parameters that match your specific needs.

Generate an RSA private key

In this guide, you'll create the simplest possible RSA key and verify its validity with the OpenSSL command-line tool:

Navigate to Digital Certificates → Private keys and click Create private key.

Fill in the General section of the private key form.

Name	`RSA`
Key algorithm	`RSA`
Key size	`2048 bit`

Scroll down to Security and set encryption to None. Click Save when done.

Encryption

None

The RSA key appears in the grid.

Click the key's Export button, choose the format, and click Export to download the key as RSA.pem.

Format	`PEM`
Encryption	`None`

Use the OpenSSL command-line tool to view the key's content and verify its validity:

View the RSA key's content
$ openssl rsa -in ~/Downloads/RSA.pem | openssl pkey -inform PEM -text -noout
writing RSA key
Private-Key: (2048 bit, 2 primes)
modulus:
    00:c4:96:a7:80:e4:45:19:47:3f:55:48:0e:eb:da:
    ...
publicExponent: 65537 (0x10001)
privateExponent:
    2d:c0:94:3e:4a:a2:0c:46:89:26:5b:6d:61:95:cd:
    ...
prime1:
    00:f9:9f:52:03:48:2d:bf:a7:c1:9a:e5:68:51:7d:
    ...
prime2:
    00:c9:9c:75:f6:ab:49:4a:6b:85:6b:61:cc:04:20:
    ...
exponent1:
    00:be:75:85:49:e3:c4:a4:3b:07:49:7c:48:40:05:
    ...
exponent2:
    00:94:db:de:49:8b:fc:e8:62:ed:36:f5:15:92:f2:
    ...
coefficient:
    27:bf:26:e8:31:41:0c:2f:88:c7:5e:2d:af:46:c4:
    ...

Generate an ECDSA elliptic curve private key

In this guide, you'll generate an ECDSA elliptic curve private key protected by a passphrase:

Navigate to Digital Certificates → Private keys and click Create private key.

Fill in the General section with ECDSA key parameters.

Name	`ECC`
Key algorithm	`ECDSA`
Curve name	`secp384r1 / NIST P-384`

Scroll down to Security and set a passphrase to protect the key. Click Save when done.

Encryption	`Passphrase`
Passphrase	`pass`
Repeat passphrase	`pass`

The ECDSA key appears in the grid.

Click the key's Export button, choose the format, enter the current and export passphrases, and click Export to download the key as ECC.p8.

Format	`PKCS#8`
Current passphrase	`pass`
Export passphrase	`pass-export`
Repeat export passphrase	`pass-export`

Use the OpenSSL command-line tool to view the key's content and verify its validity:

View the ECDSA key's content
$ openssl pkcs8 -inform DER -in ~/Downloads/ECC.p8 -passin pass:pass-export | \
    openssl pkey -inform PEM -text -noout
Private-Key: (384 bit)
priv:
    8c:30:d7:b2:df:7c:9d:75:cb:a0:ec:93:53:ea:91:
    ...
pub:
    04:f8:94:f2:28:f7:be:e7:75:ff:8d:3a:0d:c9:d3:
    ...
ASN1 OID: secp384r1
NIST CURVE: P-384

Generate an RSA private key​

Generate an ECDSA elliptic curve private key​

Generate an RSA private key

Generate an ECDSA elliptic curve private key