`
shappy1978
  • 浏览: 698547 次
  • 性别: Icon_minigender_1
  • 来自: 广州
社区版块
存档分类
最新评论

Comment of Encryption

 
阅读更多

* AES/DES

Java and .NET use PKCS5Padding by default

Java use ECBMode by default,

ObjC use CBCMode and PKCS7Padding by default, can support NoPadding and PKCS7Padding 2 modes only.

 

* RSA

Java default RSA/None/PKCS1Padding

Android default: RSA/None/NoPadding 

It's identical to "RSA/ECB/PKCS1Padding" where ECB is a bit of a misnomer, as it does not implement a block cipher mode of encryption. "RSA/None/PKCS1Padding" would have been a better name. Or "RSA/None/RSASSA-PKCS1-v1_5" as your guess about the padding mechanism is correct. This means that it uses a older mode of encryption (OAEP is better and newer). It also means that the input is restricted to a maximum of the key size minus 11 bytes.

 http://stackoverflow.com/questions/21066902/default-rsa-padding-in-sun-jce-oracle-jce

 

Key length 12-128 bytes

http://blog.csdn.net/centralperk/article/details/8553759

Encryption systems are often grouped into families. Common families include symmetric systems (e.g. AES) and asymmetric systems (e.g. RSA); they may alternatively be grouped according to the central algorithm used (e.g. elliptic curve cryptography).

As each of these is of a different level of cryptographic complexity, it is usual to have different key sizes for the same level of security, depending upon the algorithm used. For example, the security available with a 1024-bit key using asymmetric RSA is considered approximately equal in security to an 80-bit key in a symmetric algorithm (Source: RSA Security).

The actual degree of security achieved over time varies, as more computational power and more powerful mathematical analytic methods become available. For this reason cryptologists tend to look at indicators that an algorithm or key length shows signs of potential vulnerability, to move to longer key sizes or more difficult algorithms. For example as of May 2007[update], a 1039 bit integer was factored with the special number field sieve using 400 computers over 11 months.[1] The factored number was of a special form; the special number field sieve cannot be used on RSA keys. The computation is roughly equivalent to breaking a 700 bit RSA key. However, this might be an advance warning that 1024 bit RSA used in secure online commerce should be deprecated, since they may become breakable in the near future. Cryptography professor Arjen Lenstra observed that "Last time, it took nine years for us to generalize from a special to a nonspecial, hard-to-factor number" and when asked whether 1024-bit RSA keys are dead, said: "The answer to that question is an unqualified yes."[2]

he effectiveness of public key cryptosystems depends on the intractability (computational and theoretical) of certain mathematical problems such as integer factorization. These problems are time consuming to solve, but usually faster than trying all possible keys by brute force. Thus, asymmetric algorithm keys must be longer for equivalent resistance to attack than symmetric algorithm keys. As of 2002, an asymmetric key length of 1024 bits was generally considered[who?] the minimum necessary for the RSA encryption algorithm.

As of 2003[update] RSA Security claims that 1024-bit RSA keys are equivalent in strength to 80-bit symmetric keys, 2048-bit RSA keys to 112-bit symmetric keys and 3072-bit RSA keys to 128-bit symmetric keys. RSA claims that 1024-bit keys are likely to become crackable some time between 2006 and 2010 and that 2048-bit keys are sufficient until 2030. An RSA key length of 3072 bits should be used if security is required beyond 2030.[6] NIST key management guidelines further suggest that 15360-bit RSA keys are equivalent in strength to 256-bit symmetric keys.[7]

The Finite Field Diffie-Hellman algorithm has roughly the same key strength as RSA for the same key sizes. The work factor for breaking Diffie-Hellman is based on the discrete logarithm problem, which is related to the integer factorization problem on which RSA's strength is based. Thus, a 3072-bit Diffie-Hellman key has about the same strength as a 3072-bit RSA key.

 http://en.wikipedia.org/wiki/Key_size 

 

 

 

 

 

分享到:
评论

相关推荐

    加密的艺术-the art of encryption.pdf

    ### 加密的艺术——详解加密与解密流程 #### 加密技术概述 在现代信息技术领域,加密技术被视为确保数据安全和隐私的重要手段之一。通过加密,原始数据(明文)可以被转换成一种难以理解的形式(密文),从而保护...

    同态加密算法Fully Homomorphic Encryption over the Integers

    However, instead of using ideal lattices over a polynomial ring, our bootstrappable encryption scheme merely uses addition and multiplication over the integers. The main appeal of our scheme is the ...

    Advanced Folder Encryption 6.60

    The program can encrypt, lock, and password protect all of your folders and files all at the same time quickly and easily. The program integrates with Windows Explorer so you can enable decryption, ...

    ANSI-X9 52-1998 Triple Data Encryption Algorithm Modes of Operation

    ANSI-X9.52-1998标准详细介绍了Triple Data Encryption Algorithm(TDEA)的运行模式,这是一项在金融服务业中使用的加密技术。TDEA也被称为3DES(Triple DES),是一种对称密钥加密算法,它通过三次应用DES(Data ...

    encryption.jar工具.zip

    《Spring加密工具包详解——以encryption.jar为例》 在当今数字化时代,数据安全的重要性不言而喻,尤其是在处理大量敏感信息的大数据环境中。Spring作为Java领域广泛应用的框架,其提供的工具包不仅支持业务逻辑的...

    Block Cipher Modes of Operation-Methods for Format-Preserving Encryption.pdf

    Recommendation for Block Cipher Modes of Operation- Methods for Format-Preserving Encryption; 格式保留加密;FF1,FF3

    Security analysis of optical encryption

    光学加密是指利用光的物理特性进行数据加密的技术,它是一种应用光学信息处理系统来实现数据安全和验证的方法。光学加密技术的出现源于光学系统所具有的内在并行性、信息处理的光速以及在空间域或空间频率域操纵信息...

    sqlserver 存储过程With Encryption加密的解密

    ### SQL Server 存储过程 With Encryption 加密的解密方法 #### 背景与目的 在SQL Server中,为了保护存储过程中的敏感代码或逻辑,可以使用`WITH ENCRYPTION`选项对存储过程进行加密处理。这可以有效防止未经授权...

    On the Security of Homomorphic Encryption on Approximate Numbers

    在《On the Security of Homomorphic Encryption on Approximate Numbers》这篇论文中,作者Baiyu Li和Daniele Micciancio关注的是针对近似数值的同态加密(Homomorphic Encryption, HE)方案的安全性,特别是对CKKS...

    CSA Cloud Data Encryption Guidelines.pdf

    CSA Cloud Data Encryption Guideline, 有助CISSP, CCSP 等考試

    C++加解密试例,Encryption and Decryption of Text

    c C++加解密试例 Encryption and Decryption of Text

    Image encryption_image_encryption_

    Image encryption scheme with bit-level scrambling and multiplication diffusion"的研究中,作者可能提出了一个结合这两种技术的新颖加密算法。该算法首先对图像的每个像素进行位级扰动,然后应用乘法扩散过程,...

    Encryption加密

    Laravel官方文档讲解,该资料是一整套视频,需要逐个下载,Encryption加密

    data encryption

    data encryption technology and algorithsm.very good for begginer

    PGP Desktop Whole Disk Encryption 教程

    ### PGP Desktop Whole Disk Encryption 教程 #### 一、PGP Desktop Whole Disk Encryption 概述 PGP Desktop Whole Disk Encryption 是一款强大的数据保护软件,主要用于个人电脑与笔记本电脑等设备上的硬盘整体...

    针对sqlserver 2008 存储过程通过With Encryption加密方式的解密

    针对 SQL Server 2008 存储过程通过 With Encryption 加密方式的解密 SQL Server 2008 存储过程中使用 With Encryption 加密方式可以对存储过程进行加密保护,以防止未经授权的访问和修改。但是,在某些情况下,...

    Cryptanalysis of an Image Encryption Using 2D Henon-Sine Map and DNA Approach

    Cryptanalysis of an Image Encryption Using 2D Henon-Sine Map and DNA Approach

    DES encryption and decryption.

    It consists of two files, enc.cpp for encryption and dec.cpp for decryption. The input text file is should be named "i.txt" (without the quotes) in c:\ directory. I used turbo c++ compiler on ...

    Minva Encryption Pro 6.0

    If you need setup file of Minva Encryption Pro 6.0, please connect with Minva Customer Service. Minva Customer Service: Email: LqrService@yahoo.com.cn Skype Account: MinvaService URL: ...

Global site tag (gtag.js) - Google Analytics