ecparam.1s

openssl ecparam [-help] [-list_curves] [-genkey] [-name curve_name] [-out filename] [-noout] [-text] [-C] [-param_enc encoding]

-help
    Display a brief usage message.

-list_curves
    List available named curves.

-genkey
    Generate a new key using the specified parameters (or a default curve if none is specified).

-name curve_name
    Use the specified named curve. See the list generated by -list_curves.

-out filename
    Output the parameters to the specified file.

-noout
    Do not output the encoded version of the parameters.

-text
    Print a human-readable text version of the parameters.

-C
    Output a C language source file fragment.

-param_enc encoding
    Specify the encoding format of the parameters. Can be 'DER' or 'PEM'.

The ecparam command is a versatile tool used to generate, verify, and display Elliptic Curve Cryptography (ECC) parameters. It supports a range of named curves as well as the ability to generate custom curves with specific parameters. Its primary function is to create or validate ECC parameter sets suitable for use with other OpenSSL commands and applications. These parameters are essential for various cryptographic operations, including key generation, digital signatures (ECDSA), and key exchange (ECDH). The command allows you to output parameters in various formats, including PEM, which is commonly used for storing cryptographic keys and certificates.

ecparam is a crucial tool for setting up and managing secure communication channels and cryptographic systems. It facilitates the generation of strong and reliable ECC parameters, ensuring the integrity and confidentiality of data.
It is commonly used to generate ECC parameters for use with tools like `openssl genpkey` and `openssl ec`.
It can also be used to check existing parameters.

The security of ECC relies heavily on the chosen curve and its implementation. Always use recommended and well-vetted curves. Be aware of potential side-channel attacks when implementing ECC in hardware or software.
Care should be taken when generating custom curves to ensure that they are secure and not susceptible to known attacks. It is generally recommended to use established named curves whenever possible.

When working with ECC, it is crucial to use parameters and curves that have been thoroughly analyzed and are considered secure. Avoid using custom curves unless you have expert knowledge of ECC cryptography. Regularly update your OpenSSL installation to benefit from the latest security patches and improvements.

The `ecparam` command has been a part of the OpenSSL suite for many years, evolving alongside advancements in ECC cryptography. It originally provided a means to generate parameters for a limited set of curves. Over time, it has been enhanced to support a wider range of named curves and custom curve generation. Its usage has increased as ECC has become a more prevalent cryptographic algorithm, particularly in applications such as TLS/SSL, digital signatures, and blockchain technologies. Its development mirrors the increasing need for secure and efficient public-key cryptography.

openssl(1), openssl-genpkey(1), openssl-ec(1)