{
                        X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
			store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);

            
			X509Certificate2Collection collection = store.Certificates.Find(X509FindType.FindBySubjectName, signerName, true);
			X509Certificate2 cert = collection[0];
                        filename = Sign(filename, cert);
			Encrypt(filename, cert);
                        }

                private static string Sign(string filename, X509Certificate2 cert)
		{
			byte[] data = ReadFile(filename);
			ContentInfo contentInfo = new ContentInfo(data);
			SignedCms signedCms = new SignedCms(contentInfo);
			CmsSigner cmsSigner = new CmsSigner(cert);
			signedCms.ComputeSignature(cmsSigner, false);

			byte[] signed = signedCms.Encode();
			Console.WriteLine("Signed bytes size: {0}", signed.Length);

			string signedStr = Convert.ToBase64String(signed);

			string signedFilename = filename + ".sig";
			File.WriteAllBytes(signedFilename, Encoding.UTF8.GetBytes(signedStr));

			return signedFilename;
		}

		private static void Encrypt(string filename, X509Certificate2 cert)
		{
			byte[] data = ReadFile(filename);

			ContentInfo content = new ContentInfo(data);
			EnvelopedCms envelopedCms = new EnvelopedCms(content);
			CmsRecipient recip1 = new CmsRecipient(
				SubjectIdentifierType.IssuerAndSerialNumber, cert);
			envelopedCms.Encrypt(recip1);
			byte[] envelopedbytes = envelopedCms.Encode();

			string envelopedBytesStr = Convert.ToBase64String(envelopedbytes);

			string encryptedFilename = filename + ".enc";
			File.WriteAllBytes(encryptedFilename, Encoding.UTF8.GetBytes(envelopedBytesStr));
		}