Java安全學習－－訊息摘要（MessageDigest）

MessageDigest（訊息摘要）

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訊息摘要的演算法主要有以下幾種：

MD2: The MD2 message digest algorithm as defined in RFC 1319.

MD5: The MD5 message digest algorithm as defined in RFC 1321.

SHA-1: The Secure Hash Algorithm, as defined in Secure Hash Standard, NIST FIPS 180-1.

SHA-256, SHA-384, and SHA-512:New hash algorithms for which the draft Federal Information Processing Standard 180-2, Secure Hash Standard (SHS) is now available. SHA-256 is a 256-bit hash function intended to provide 128 bits of security against collision attacks, while SHA-512 is a 512-bit hash function intended to provide 256 bits of security. A 384-bit hash may be obtained by truncating the SHA-512 output.

我們熟悉的有MD5和SHA。

我們可以通過下來的方法得到MessageDigest的執行個體。

MessageDigest  md = MessageDigest.getIntance("MD5");