Install the cryptography Library for Python

Linux

Step 1: Check Python and pip

python3 --version && pip --version

Step 2: Install the package

pip install cryptography

On new Linux systems (Debian 12, Ubuntu 23.04 and newer) pip may refuse with error: externally-managed-environment. This protects the system Python. Use a virtual environment:

python3 -m venv myenv
source myenv/bin/activate
pip install cryptography

Step 3: Check the install

pip show cryptography

python -c "import cryptography; print(cryptography.__version__)"

Windows

Step 1: Check Python and pip

python --version
pip --version

Step 2: Install the package

pip install cryptography

Step 3: Check the install

pip show cryptography

python -c "import cryptography; print(cryptography.__version__)"

Troubleshooting

If the build fails on Linux, install the build tools and the headers:

sudo apt install build-essential libssl-dev libffi-dev python3-dev

On Red Hat based systems: sudo dnf install gcc openssl-devel libffi-devel python3-devel.

Upgrade pip if you see build errors, because new pip versions install ready-made wheels:

python3 -m pip install --upgrade pip

A quick example

from cryptography.fernet import Fernet

key = Fernet.generate_key()
f = Fernet(key)
token = f.encrypt(b"secret message")
print(f.decrypt(token))

Quick recap

• pip install cryptography, in a virtual environment on new Linux systems.
• Check with pip show cryptography.
• Install the build tools if the install fails.