U need to download
DotNetZip.Dll file and use..
Below is some very stripped down code showing the process:
using (ZipFile zipFile = new ZipFile())
{
foreach (var uri in uriCollection)
{
var blob = new CloudBlob(uri);
byte[] fileBytes = blob.DownloadByteArray();
using (var fileStream = new MemoryStream(fileBytes))
{
fileStream.Seek(0, SeekOrigin.Begin);
byte[] bytes = CryptoHelp.EncryptAsBytes(fileStream, "password", null);
zipFile.AddEntry("entry name", bytes);
}
}
using (var zipStream = new MemoryStream())
{
zipFile.Save(zipStream);
zipStream.Seek(0, SeekOrigin.Begin);
var blobRef = ContainerDirectory.GetBlobReference("output uri");
blobRef.UploadFromStream(zipStream);
}
}