If you want to see whether your dll is strongly signed or not you can check that via Reflector. Load your dll in Reflector and focus on PublicKeyToken value. Reflector will show you information like this:
// Assembly Newtonsoft.Json, Version 220.127.116.11
If it is showing some value of PublicKeyToken that means it is signed i.e strongly named and if it is showing it null this means it is not.