page 1:
-	"massively eavesdrop"?  not wording i would ever use.. what do you mean here, it doesn't seem to be "easily eavesdrop"..
-	"for business as well as" - do you mean "for business_es_ as well as", or "for both business and private communication"?
-	"not widely used is that the existing applications, which use cryptography, are very complicated"
	change to "not widely used is that the existing applications that use cryptography are very complicated"

page 2:
- "into all parts avoiding complexity" -> "into all parts, avoiding complexity"
- "compatibility to old insecure" -> "compatibility with old insecure"
- "new developed network components" -> "newly developed network components" ..?
- "the appendix informs about the legal" -> "the appendix discusses the legal"

page 75:
-	"security as afterthought" -> "security as an afterthought"
- "from ground up" -> "from the ground up"
-	"This makes it possible that all information transmitted between two users is signed and encrypted."
		-> "This makes it possible for all information transmitted between two users to be signed and encrypted."
- "composed out of a hierarchy" -> "composed of a hierarchy"
- "This method allows it to use cryptography"... "it" is ambiguous here... change to Secos?

page 76:
-	"The third and most practical protection".. change to "The third and most practical method of protection"?
-	"Very interesting is the implementation of further functionality:" ...what do you mean by this?  will need to talk about this.
- "chat with three and more persons" -> "chat with three or more people"
- "Secure reading confirmations for mails" .. "Secure reading confirmation for mail"?
- "can be used as application enabler." -> "can be used as an application enabler."