If your own company is an enemy then you have a problem. Or possibly you are the problem.
Normally, you connect your machine on the company's network based on a contractual agreement which makes you the employee, and defines your rights and duties. In particular, many companies do not allow employees to plug their own hardware on the company network; or when that is allowed, there are technical requirements, such as installing specific sysadmin software provided by the company itself. This is what occurs in most cases where BYOD is applied.
These technical and contractual agreements notably allow or disallow interception by network administrators. So your question really sounds as a request for specific advices in order to do something illegal. This is usually not well tolerated here.
However, I can still give a neutral and technical answer. SSL protects against malicious passive and active eavesdropping and data alteration, in particular Man-in-the-Middle interception (which is "just" double impersonation: the client talks to a fake server, the server talks to a fake client). This property is ensured based on root assumptions:
- The server's certificate can be reliably validated by the client, relatively to a set of root CA, as known by the client, who are all honest.
- The client's software is not maliciously modified.
If a third party wants to see what data is exchanged between your machine and some given external server, then one of these assumptions must not hold. In the case of Blue Coat's ProxySG product, that's the first one: as part of ProxySG's deployment, a new root CA, controlled by that ProxySG installation, is generated and must be installed in the client systems. If no such root CA was installed in your machine, then Blue Coat's ProxySG won't be able to enact its interception. At least not silently: your browser will warn about how every SSL-powered Web site seems to use a certificate from an unknown CA.
A noteworthy point is that if you are in the habit of "clicking through" browser warnings, i.e. instructing your browser to connect nonetheless, despite an invalid or unverifiable server certificate, then your security against MitM goes down the drain, by your own actions.
Another noteworthy point is that though SSL protects the data contents, external eavesdroppers can still work out what servers you are talking to, and make general guesses at the nature of the exchanges based on their timing and their size. When you connect to Facebook, your employer does not need to see the data contents to realize that your are slacking away instead of doing your job.
Finally, Skype does not use SSL but its own protocol, which may or may not be safe (protocol details are not really published, and not really clear either).