# Basic secure deletion (3 passes)
shred -vfz -n 3 sensitive_file.txt

# DoD 5220.22-M standard (7 passes)
shred -vfz -n 7 file.pdf

# Gutmann method (35 passes)
shred -vfz -n 35 top_secret.doc

# Delete and remove file
shred -vfzu -n 3 file.txt

# Secure delete entire directory
find /path/to/dir -type f -exec shred -vfzu -n 3 {} \;

# Install srm
sudo apt-get install secure-delete

# Simple deletion (7 passes)
srm file.txt

# Fast deletion (1 pass)
srm -f file.txt

# Recursive directory deletion
srm -r /path/to/directory

# DoD compliant
srm -D file.txt

# Wipe file with default passes
wipe file.txt

# Quick wipe (4 passes)
wipe -q file.txt

# Recursive wipe
wipe -r directory/

# Force wipe (no confirmation)
wipe -f file.txt

# Overwrite file with zeros
dd if=/dev/zero of=file.txt bs=1M count=10

# Overwrite with random data
dd if=/dev/urandom of=file.txt bs=1M count=10

# Wipe entire disk/partition (BE CAREFUL!)
sudo dd if=/dev/zero of=/dev/sdX bs=1M status=progress

# Wipe free space on partition
sfill -f /mount/point

# Quick free space wipe
sfill -I /mount/point

# Wipe swap space
sudo swapoff -a
sudo dd if=/dev/zero of=/dev/swap_partition
sudo mkswap /dev/swap_partition
sudo swapon -a

# TRIM (marks blocks for deletion)
sudo fstrim -v /mount/point

# Secure Erase (ATA command)
sudo hdparm --user-master u --security-set-pass password /dev/sdX
sudo hdparm --user-master u --security-erase password /dev/sdX

# Encryption before deletion
cryptsetup luksFormat /dev/sdX
# Then delete encryption key

import os
import random
import hashlib

class SecureDelete:
    def secure_delete_file(self, filepath, passes=3):
        """Securely delete file with multiple overwrites"""
        file_size = os.path.getsize(filepath)

        with open(filepath, "ba+", buffering=0) as f:
            for pass_num in range(passes):
                f.seek(0)
                if pass_num == 0:
                    # First pass: zeros
                    f.write(b'\x00' * file_size)
                elif pass_num == 1:
                    # Second pass: ones
                    f.write(b'\xFF' * file_size)
                else:
                    # Subsequent passes: random data
                    f.write(os.urandom(file_size))
                f.flush()
                os.fsync(f.fileno())

        # Delete the file
        os.remove(filepath)
        print(f"Securely deleted: {filepath} ({passes} passes)")

    def verify_deletion(self, filepath):
        """Verify file no longer exists"""
        return not os.path.exists(filepath)

    def secure_delete_directory(self, dirpath, passes=3):
        """Recursively secure delete directory"""
        for root, dirs, files in os.walk(dirpath, topdown=False):
            for name in files:
                filepath = os.path.join(root, name)
                self.secure_delete_file(filepath, passes)
            for name in dirs:
                os.rmdir(os.path.join(root, name))
        os.rmdir(dirpath)