Motorola SVG1501UE, SVG1501E manual Phase 1 DH group, Phase 1 encryption, Phase 1 authentication

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Field	Description
Phase 1 DH group	Select one of the Diffie-Hellman groups: 768 bits, 1024 bits, or
	1536 bits.
	Diffie-Hellman is a cryptographic technique that uses public
	and private keys for encryption and decryption. The higher the
	number of bits, the more secure the encryption. Options:
	Group 1 (768 bits), Group 2 (1024 bits), or Group 5 (1536 bits).
Phase 1 encryption	Secure the VPN connection between endpoints: DES, 3DES,
	AES-128, AES-192, or AES-256.
	Select any encryption but make the far endpoints match.
	Common encryption settings are 3DES and AES.
Phase 1 authentication	Set Authentication, another level of security, to SHA or MD5
	Motorola recommends SHA because it is more secure but you
	can use either authentication provided the other end of the
	VPN tunnel uses the same method.
Phase 1 SA lifetime	Specify the lifetime of individual rotating keys.
	Enter the number of seconds for the key to last until a re-key
	negotiation between each endpoint is negotiated. The default
	setting is 28,800 seconds.
	A smaller lifetime is generally more secure, since it would give
	an attacker a smaller amount of time to try to crack the key,
	however key negotiation takes up bandwidth, so network
	throughput is sacrificed with small lifetimes. Entries are
	typically in the thousands or tens of thousands of seconds.

10 • VPN Pages 62