What are some of the crypto-related best practices recommended in the operation of a VPN?

"Businesses that understand the need for encryption and how it protects the privacy of electronic documents also understand how data can be compromised and the need for the emergency recovery of the data. This can be done by saving an individual's private key information, encrypting it with a trusted third party's key, or saving all keys used to encrypt all documents. Whichever methodology is used, some mechanism is needed to recover encrypted files owned by an individual. Additionally, recovery of session keys used to encrypt a network connection is a law enforcement requirement. Therefore, VPNs must use the strongest available crypto compatible with the hardware on which it is being run. Weak cryptography should be completely avoided."