using System.Security.Cryptography;
using System.Text;

public static class SaveHash
{
    const string SECRET = "phoque-mange-mieux-et-code-plus";

    public static string Compute(string data)
    {
        using SHA256 sha = SHA256.Create();
        byte[] bytes = Encoding.UTF8.GetBytes(data + SECRET);
        byte[] hash = sha.ComputeHash(bytes);

        StringBuilder sb = new StringBuilder();
        foreach (byte b in hash)
            sb.Append(b.ToString("x2"));

        return sb.ToString();
    }
}