rsa加密長度

❶ 請教基於java的rsa加密如何去掉加密明文長度的限制

既然高並發了務必要考慮吞吐量吧，進行同步不是一個好的選擇。其實你可以把加密演算法與私鑰封裝進一個類里，然後每次請求實例化這個類，創建一個實體，之後進行解密就行了。

❷ php中RSA加密，明文超長，需要分段加密該怎麼做

這方面的話我不是很了解，一般來說，加密分為兩個部分，一個是非對稱加密，一個是對稱加密，使用對稱加密加密正文信息，使用非對稱加密加密對稱加密的密鑰，然後發送加密數據(消息摘要和數字簽名就不討論了)，這是正規的數據加密策略，對稱加密默認支持大數據分段加密策略，你只需要從介面中完成加密即可，而且對稱加密速度比非對稱加密快很多，如果你需要使用這個策略建議使用AES。
如果你不願意使用對稱加密，只願意使用AES加密，那你就必須喪失速度了，而且自己處理分段加密，因為RSA加密通常是117個位元組就要分段(這個長度可能和密鑰長度有關，我是用的介面是117)，你需要自己把數據變成N個117位元組的數據段來完成加密，解密也需要自己完成位元組拼裝。詳細還是建議你去後盾人平台去看看視頻教學吧，那裡面有的，講的很清楚。

❸ 1024位的RSA加密速度到2015年最快達到多少2048位的呢

RSA的演算法現在基本是固定的，加密速度和你的硬體有關，硬體越好，速度越快。
雖然說RSA算是比較慢的一種加密演算法了，但是他的安全性很好，幾乎沒有一種完善的破解方式，而且就目前來說，速度也還能接受，算是比較主流的一種數據加密方式。許多https證書加密就是RSA，而且是2048位的加密。
但要是說具體有多快就不清楚了。

❹ 有關C#中RSA加密方法的密鑰生成長度

/// <summary> /// 字元串加密操作類
/// </summary>
public class EncryptionOperation
{
/// <summary>

/// MD5 加密靜態方法
/// </summary>
/// <param name="EncryptString">待加密的密文</param>
/// <returns>returns</returns>
public static string MD5Encrypt(string EncryptString) {
if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception("密文不得為空")); }

MD5 m_ClassMD5 = new MD5CryptoServiceProvider();

string m_strEncrypt = "";

try {
m_strEncrypt = BitConverter.ToString(m_ClassMD5.ComputeHash(Encoding.Default.GetBytes(EncryptString))).Replace("-", "");
}
catch (ArgumentException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_ClassMD5.Clear(); }

return m_strEncrypt;
}

/// <summary>
/// DES 加密(數據加密標准，速度較快，適用於加密大量數據的場合)
/// </summary>
/// <param name="EncryptString">待加密的密文</param>
/// <param name="EncryptKey">加密的密鑰</param>
/// <returns>returns</returns>
public static string DESEncrypt(string EncryptString, string EncryptKey) {
if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(EncryptKey)) { throw (new Exception("密鑰不得為空")); }

if (EncryptKey.Length != 8) { throw (new Exception("密鑰必須為8位")); }

byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

string m_strEncrypt = "";

DESCryptoServiceProvider m_DESProvider = new DESCryptoServiceProvider();

try {
byte[] m_btEncryptString = Encoding.Default.GetBytes(EncryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_cstream = new CryptoStream(m_stream, m_DESProvider.CreateEncryptor(Encoding.Default.GetBytes(EncryptKey), m_btIV), CryptoStreamMode.Write);

m_cstream.Write(m_btEncryptString, 0, m_btEncryptString.Length);

m_cstream.FlushFinalBlock();

m_strEncrypt = Convert.ToBase64String(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_cstream.Close(); m_cstream.Dispose();
}
catch (IOException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (ArgumentException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_DESProvider.Clear(); }

return m_strEncrypt;
}
/// <summary>
/// DES 解密(數據加密標准，速度較快，適用於加密大量數據的場合)
/// </summary>
/// <param name="DecryptString">待解密的密文</param>
/// <param name="DecryptKey">解密的密鑰</param>
/// <returns>returns</returns>
public static string DESDecrypt(string DecryptString, string DecryptKey) {
if (string.IsNullOrEmpty(DecryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(DecryptKey)) { throw (new Exception("密鑰不得為空")); }

if (DecryptKey.Length != 8) { throw (new Exception("密鑰必須為8位")); }

byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

string m_strDecrypt = "";

DESCryptoServiceProvider m_DESProvider = new DESCryptoServiceProvider();

try {
byte[] m_btDecryptString = Convert.FromBase64String(DecryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_cstream = new CryptoStream(m_stream, m_DESProvider.CreateDecryptor(Encoding.Default.GetBytes(DecryptKey), m_btIV), CryptoStreamMode.Write);

m_cstream.Write(m_btDecryptString, 0, m_btDecryptString.Length);

m_cstream.FlushFinalBlock();

m_strDecrypt = Encoding.Default.GetString(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_cstream.Close(); m_cstream.Dispose();
}
catch (IOException ex) {
m_strDecrypt = "";
}

catch (CryptographicException ex) { m_strDecrypt = ""; }
catch (ArgumentException ex) { m_strDecrypt = ""; }
catch (Exception ex) { m_strDecrypt = ""; }
finally { m_DESProvider.Clear(); }

return m_strDecrypt;
}
/// <summary>
/// RC2 加密(用變長密鑰對大量數據進行加密)
/// </summary>
/// <param name="EncryptString">待加密密文</param>
/// <param name="EncryptKey">加密密鑰</param>
/// <returns>returns</returns>
public static string RC2Encrypt(string EncryptString, string EncryptKey) {
if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(EncryptKey)) { throw (new Exception("密鑰不得為空")); }

if (EncryptKey.Length < 5 || EncryptKey.Length > 16) { throw (new Exception("密鑰必須為5-16位")); }

string m_strEncrypt = "";

byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

RC2CryptoServiceProvider m_RC2Provider = new RC2CryptoServiceProvider();

try {
byte[] m_btEncryptString = Encoding.Default.GetBytes(EncryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_cstream = new CryptoStream(m_stream, m_RC2Provider.CreateEncryptor(Encoding.Default.GetBytes(EncryptKey), m_btIV), CryptoStreamMode.Write);

m_cstream.Write(m_btEncryptString, 0, m_btEncryptString.Length);

m_cstream.FlushFinalBlock();

m_strEncrypt = Convert.ToBase64String(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_cstream.Close(); m_cstream.Dispose();
}
catch (IOException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (ArgumentException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_RC2Provider.Clear(); }

return m_strEncrypt;
}
/// <summary>
/// RC2 解密(用變長密鑰對大量數據進行加密)
/// </summary>
/// <param name="DecryptString">待解密密文</param>
/// <param name="DecryptKey">解密密鑰</param>
/// <returns>returns</returns>
public static string RC2Decrypt(string DecryptString, string DecryptKey) {
if (string.IsNullOrEmpty(DecryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(DecryptKey)) { throw (new Exception("密鑰不得為空")); }

if (DecryptKey.Length < 5 || DecryptKey.Length > 16) { throw (new Exception("密鑰必須為5-16位")); }

byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

string m_strDecrypt = "";

RC2CryptoServiceProvider m_RC2Provider = new RC2CryptoServiceProvider();

try {
byte[] m_btDecryptString = Convert.FromBase64String(DecryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_cstream = new CryptoStream(m_stream, m_RC2Provider.CreateDecryptor(Encoding.Default.GetBytes(DecryptKey), m_btIV), CryptoStreamMode.Write);

m_cstream.Write(m_btDecryptString, 0, m_btDecryptString.Length);

m_cstream.FlushFinalBlock();

m_strDecrypt = Encoding.Default.GetString(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_cstream.Close(); m_cstream.Dispose();
}
catch (IOException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (ArgumentException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_RC2Provider.Clear(); }
return m_strDecrypt;
}
/// <summary>
/// 3DES 加密(基於DES，對一塊數據用三個不同的密鑰進行三次加密，強度更高)
/// </summary>
/// <param name="EncryptString">待加密密文</param>
/// <param name="EncryptKey1">密鑰一</param>
/// <param name="EncryptKey2">密鑰二</param>
/// <param name="EncryptKey3">密鑰三</param>
/// <returns>returns</returns>
public static string DES3Encrypt(string EncryptString, string EncryptKey1, string EncryptKey2, string EncryptKey3) {
string m_strEncrypt = "";

try {
m_strEncrypt = DESEncrypt(EncryptString, EncryptKey3);

m_strEncrypt = DESEncrypt(m_strEncrypt, EncryptKey2);

m_strEncrypt = DESEncrypt(m_strEncrypt, EncryptKey1);
}
catch (Exception ex) { throw ex; }

return m_strEncrypt;
}
/// <summary>
/// 3DES 解密(基於DES，對一塊數據用三個不同的密鑰進行三次加密，強度更高)
/// </summary>
/// <param name="DecryptString">待解密密文</param>
/// <param name="DecryptKey1">密鑰一</param>
/// <param name="DecryptKey2">密鑰二</param>
/// <param name="DecryptKey3">密鑰三</param>
/// <returns>returns</returns>
public static string DES3Decrypt(string DecryptString, string DecryptKey1, string DecryptKey2, string DecryptKey3) {
string m_strDecrypt = "";

try {
m_strDecrypt = DESDecrypt(DecryptString, DecryptKey1);

m_strDecrypt = DESDecrypt(m_strDecrypt, DecryptKey2);

m_strDecrypt = DESDecrypt(m_strDecrypt, DecryptKey3);
}
catch (Exception ex) { throw ex; }

return m_strDecrypt;
}
/// <summary>
/// AES 加密(高級加密標准，是下一代的加密演算法標准，速度快，安全級別高，目前 AES 標準的一個實現是 Rijndael 演算法)
/// </summary>
/// <param name="EncryptString">待加密密文</param>
/// <param name="EncryptKey">加密密鑰</param>
/// <returns></returns>
public static string AESEncrypt(string EncryptString, string EncryptKey) {
if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(EncryptKey)) { throw (new Exception("密鑰不得為空")); }

string m_strEncrypt = "";

byte[] m_btIV = Convert.FromBase64String("Rkb4jvUy/ye7Cd7k89QQgQ==");

Rijndael m_AESProvider = Rijndael.Create();

try {
byte[] m_btEncryptString = Encoding.Default.GetBytes(EncryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_csstream = new CryptoStream(m_stream, m_AESProvider.CreateEncryptor(Encoding.Default.GetBytes(EncryptKey), m_btIV), CryptoStreamMode.Write);

m_csstream.Write(m_btEncryptString, 0, m_btEncryptString.Length); m_csstream.FlushFinalBlock();

m_strEncrypt = Convert.ToBase64String(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_csstream.Close(); m_csstream.Dispose();
}
catch (IOException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (ArgumentException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_AESProvider.Clear(); }

return m_strEncrypt;
}
/// <summary>
/// AES 解密(高級加密標准，是下一代的加密演算法標准，速度快，安全級別高，目前 AES 標準的一個實現是 Rijndael 演算法)
/// </summary>
/// <param name="DecryptString">待解密密文</param>
/// <param name="DecryptKey">解密密鑰</param>
/// <returns></returns>
public static string AESDecrypt(string DecryptString, string DecryptKey) {
if (string.IsNullOrEmpty(DecryptString)) { throw (new Exception("密文不得為空")); }

if (string.IsNullOrEmpty(DecryptKey)) { throw (new Exception("密鑰不得為空")); }

string m_strDecrypt = "";

byte[] m_btIV = Convert.FromBase64String("Rkb4jvUy/ye7Cd7k89QQgQ==");

Rijndael m_AESProvider = Rijndael.Create();

try {
byte[] m_btDecryptString = Convert.FromBase64String(DecryptString);

MemoryStream m_stream = new MemoryStream();

CryptoStream m_csstream = new CryptoStream(m_stream, m_AESProvider.CreateDecryptor(Encoding.Default.GetBytes(DecryptKey), m_btIV), CryptoStreamMode.Write);

m_csstream.Write(m_btDecryptString, 0, m_btDecryptString.Length); m_csstream.FlushFinalBlock();

m_strDecrypt = Encoding.Default.GetString(m_stream.ToArray());

m_stream.Close(); m_stream.Dispose();

m_csstream.Close(); m_csstream.Dispose();
}
catch (IOException ex) { throw ex; }
catch (CryptographicException ex) { throw ex; }
catch (ArgumentException ex) { throw ex; }
catch (Exception ex) { throw ex; }
finally { m_AESProvider.Clear(); }

return m_strDecrypt;
} }

❺ php openssl rsa 加密長度大於117，返回false,無法加密，求解決辦法

把你自己的字元串分開，每100個字元串成一個，然後分開加密相連，解密的時候也是如此

❻ RSA加密.秘鑰長度2048是不是必須是實際數位正好達到2048

你說的對。

❼ DES、RSA的明文長度和密文長度分別是多少

加密的明文長度不能超過RSA密鑰的長度-11，比如1024位的，明文長度不能超過117。 密文的長度總是密鑰的長度的一半，比如1024位的，密文長度是64，如果是1032位，密文長度是65位。

❽ rsa中為什麼加密後的長度不想同

RSA是一種塊文件加密系統，他需要將輸入的數據分成固定大小的塊，然後對這些數據塊進行加密。加密以後輸出的數據塊長度和輸入時一樣的。你發現加密後的長度不同的話，應該是RSA加密的那個padding（填充）配置不一樣，從而使得每次加密數據塊的長度不同，這樣最後出來的長度也就不一樣了。

❾ Rsa 演算法加密的數據塊大小問題

PQ的積M叫做模，模規定了這個數字空間中最大的數，是這個空間的邊界，這個空間中所有的數都要小於模M，包括被加密的消息塊。所以如果消息（a1,a2,a3...）任何一個超過了M，加密後都無法正切解密，因為加密後和解密後得到的數都在這個空間中，不可能得到一個大於M的數。

但是如果用來加密的消息A大於M，解密後得到的結果加上K倍的M一定會等於A，因為加密的過程是做模乘操作，大於M的消息A首先被除M然後取余數了，該余數一定小於M，然後所有的加密操作都是針對該余數來進行的，想要還原A的話用該A模M的余數加上數倍的M就可以了。解密的話還原的也是該余數，得到余數後還原A,也是加上數倍的M就可以了。

實質上RSA的加密有個條件，消息A必須要小於M。