PayPal accepts all major credit and debit cards and no cardholder information is ever passed unencrypted and any messages sent to our servers from PayPal are signed using MD5 hashing to prevent tampering. You can be completely assured that nothing you pass to PayPal's servers can be examined, used or modified by any third parties attempting to gain access to sensitive information.
When you pay with Paypal, all information is protected by SSL with an encryption key length of 168 bits (the highest level commercially available). Your personal information is stored on Paypal's servers and heavily guarded, both physically and electronically. To further shield your credit card and bank numbers, Paypal do not directly connect their firewall-protected servers to the internet.