Deterministic zipped string - how?

[oyevteyev]

We do compress long strings into a zipped one (password protected).
Our problem is - the output is not deterministic - every time we compress a string - we are getting a different compressed sting.
Unzipping it always returns the same result .
How to make it deterministic - the same zipped string every time?
That will help us with caching.
Thanks.
Zip:

    public string Zip(string clearText, string password)
    {
        if (clearText == null)
        {
            return null;
        }          
        using var memOutput = new MemoryStream();
        using var zipOut = new ZipOutputStream(memOutput);
        zipOut.Password = password;
        zipOut.SetLevel(3);
        var entry = new ZipEntry("state");
        zipOut.PutNextEntry(entry);
        using var writer = new StreamWriter(zipOut);
        writer.Write(clearText);
        writer.Flush();
        zipOut.Finish();
        var bytes = new byte[memOutput.Length];
        memOutput.Seek(0, SeekOrigin.Begin);
        var _ = memOutput.Read(bytes, 0, bytes.Length);
        return Convert.ToBase64String(bytes);
    }

Unzip:

  public string UnZip(string text, string password, bool isBase64Encoded = true)
    {
        if (text == null)
        {
            return null;
        }
        try
        {
            var bytes = isBase64Encoded ? Convert.FromBase64String(text) : Encoding.Unicode.GetBytes(text);
            using var memInput = new MemoryStream(bytes);
            using var zipInput = new ZipInputStream(memInput);
            zipInput.Password = password;
            zipInput.GetNextEntry();
            using var reader = new StreamReader(zipInput);
            var txt = reader.ReadToEnd();
            return txt;
        }
        catch
        {
            return "[]";
        }
    }

[piksel]

The modified time in the file is always different. Try setting the modified time manually for the entry.

[oyevteyev]

Tried, but the entry is still different each time

    public string Zip(string clearText, string password)
    {
        if (clearText == null)
        {
            return null;
        }

        var dt = new DateTime(2022, 1, 1);
        using var memOutput = new MemoryStream();
        using var zipOut = new ZipOutputStream(memOutput);
        zipOut.Password = password;
        zipOut.SetLevel(3);
        var entry = new ZipEntry("state")
        {
            DateTime = dt,
            DosTime = dt.Ticks
        };
        zipOut.PutNextEntry(entry);
        using var writer = new StreamWriter(zipOut);
        writer.Write(clearText);

        writer.Flush();
        zipOut.Finish();

        var bytes = new byte[memOutput.Length];
        memOutput.Seek(0, SeekOrigin.Begin);
        var _ = memOutput.Read(bytes, 0, bytes.Length);

        return Convert.ToBase64String(bytes);
    }