/proc/crypto: Explanation & Insights

Displays information about the cryptographic algorithms available on the system

The /proc/crypto file is a virtual file that contains information about the cryptographic algorithms, or ciphers, that the Linux kernel currently supports. These ciphers can be used for various purposes, such as data encryption, secure communication, password hashing, and more.

Significance of /proc/crypto

The /proc/crypto file serves as a quick and easy way to view what cryptographic options are available on your system. It is essential for network security and data protection. By checking this file, you can understand what encryption methods your system can use and plan your security measures accordingly.

Typical Contents of /proc/crypto

The /proc/crypto file lists all the available ciphers along with their properties. Each entry in the file represents a different cipher and provides various details such as its name, driver, module, priority, etc.

Here is a small example of what a typical /proc/crypto entry might look like:

name         : aes
driver       : aes-x86_64
module       : kernel
priority     : 200
refcnt       : 1
selftest     : passed
type         : cipher
blocksize    : 16
digestsize   : 0 

How to Use /proc/crypto

To view the contents of /proc/crypto, you can use the cat command:

cat /proc/crypto

If you want to search for a specific cipher, you can use the grep command. For instance, to check if AES cipher is available on your system, you can run:

cat /proc/crypto | grep -A 8 'name\s*:\s*aes'

This will print the details of the AES cipher if it is available.

Typical Problems and Solutions

Understanding the /proc/crypto file is crucial when you encounter security-related issues. For instance, if you are facing an encryption issue, you may need to check which ciphers are available on your system. If a required cipher is missing, you may need to load the necessary cryptographic module into the kernel.


In this blog, we went into detail about the /proc/crypto file. As a Linux user, especially if you are managing a server, understanding this file can be beneficial in maintaining the security of your system. It is always good to know what cryptographic options your system can offer, and /proc/crypto provides an easy way to find this information.

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