Name: echo
Type: response
Request: ping
Inherits: response
Elements:
	Signature: { required: true }
	From:	{ required: true }
	Date: { required: true }
	Original-Message: { required: true }
	Verification-Result: {  required: true, type: string, max_length: 128 }
	Decryption-Result: { type: string, max_length: 512 }
	Encryption-Result: { type: string, max_length: 512 }
	Public-Key:	{ required: true, type: public_key }