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ファイルの暗号化と復号化にも AES アルゴリズムを使用していますが、調査によると、このアルゴリズムのパフォーマンスは Java の RC4 アルゴリズムよりも遅くなります。このコードを使用して、C# でファイルを暗号化しています

public static class RC4
{
    public static byte[] Encrypt(byte[] key, byte[] data)
    {
        return EncryptOutput(key, data).ToArray();
    }

    private static byte[] EncryptInitalize(byte[] key)
    {
        byte[] s = Enumerable.Range(0, 256)
          .Select(i => (byte)i)
          .ToArray();

        for (int i = 0, j = 0; i < 256; i++)
        {
            j = (j + key[i % key.Length] + s[i]) & 255;

            Swap(s, i, j);
        }

        return s;
    }

    private static IEnumerable<byte> EncryptOutput(byte[] key, IEnumerable<byte> data)
    {
        byte[] s = EncryptInitalize(key);

        int i = 0;
        int j = 0;

        return data.Select((b) =>
        {
            i = (i + 1) & 255;
            j = (j + s[i]) & 255;

            Swap(s, i, j);

            return (byte)(b ^ s[(s[i] + s[j]) & 255]);
        });
    }

    private static void Swap(byte[] s, int i, int j)
    {
        byte c = s[i];

        s[i] = s[j];
        s[j] = c;
    }
}

ファイルを C# で暗号化し、このファイルを Java で復号化する必要がありますが、両方の言語の実装が見つかりませんでした。

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2 に答える 2

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Based on your comments, I am assuming you want to know how to speed up your encryption / decryption process, and changing the main algorithm is not mandatory.

You could look at different modes for AES. For example, AES in counter (CTR) mode is significantly faster than cipher block chaining (CBC) which is often used.

Try creating your cipher like

Cipher myCipher = Cipher.getInstance("AES/CTR/NoPadding");

and you should see a performance increase. Additionally, using NoPadding will keep the size the same as the plaintext.

(Yes, I know that CTR mode turn AES into a stream cipher, never mind my comment)

UPDATE

I have used this in the past along these lines: 

    Key key = new SecretKeySpec(yourKeyValue, "AES");
    Cipher enc = Cipher.getInstance("AES/CTR/NoPadding");
    enc.init(Cipher.ENCRYPT_MODE, key);
    // Get the IV that was generated
    byte[] iv = enc.getIV();
    // Encrypt your data
    ...
    Cipher dec = Cipher.getInstance("AES/CTR/NoPadding");
    dec.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
    // Decrypt your data
    ...
于 2015-08-18T21:06:03.270 に答える