雜湊產生器

關於雜湊函式

A cryptographic hash function takes any input — a single character or a megabyte of text — and produces a fixed-length hex string called a digest. The function is deterministic (same input always gives the same output) and one-way (you cannot reverse a hash back to the original text). The avalanche effect means even a one-character change in the input produces a completely different digest.

密碼學雜湊函式可以吃任何輸入 — 從一個字、到一本書 — 並輸出固定長度的十六進位字串，叫做摘要（digest）。它是確定性的（同樣輸入永遠對應同樣輸出）也是單向的（無法從雜湊反推回原文）。即使只改一個字，整段輸出就會完全不同（叫做雪崩效應）。

Which algorithm? Use SHA-256 for any modern security application — it is the standard for integrity verification, digital signatures, and TLS certificates. MD5 and SHA-1 are cryptographically broken: researchers have demonstrated practical collision attacks (two different inputs that produce the same hash). Use MD5 and SHA-1 only for non-security checksums and legacy compatibility, never for passwords, signatures, or certificates.

該選哪個演算法？現代安全用途一律用 SHA-256 — 它是完整性驗證、數位簽章、TLS 憑證的標準。MD5 與 SHA-1 在密碼學上已被破解：研究人員可以實際構造出兩段不同文字卻產出相同雜湊（碰撞攻擊）。MD5 / SHA-1 只剩下兩個用途：對舊系統的 checksum 比對、相容性驗證；絕對不可拿來放密碼、簽章、憑證。

What hashes cannot do: A hash is not encryption — there is no key and no decryption path. Hash cracking works by trying known inputs (rainbow tables, dictionary attacks) not by reversing the math. This tool uses the browser's built-in Web Crypto API (SubtleCrypto) for SHA-1, SHA-256, and SHA-512; MD5 runs via an inline pure-JS implementation because the Web Crypto API does not include it. Nothing leaves your device.

雜湊不能做的事：雜湊不是加密 — 沒有金鑰、也沒有解密路徑。所謂「破解雜湊」其實是拿已知輸入去查表（彩虹表、字典攻擊），不是反推數學。本工具用瀏覽器內建的 Web Crypto API（SubtleCrypto）算 SHA-1、SHA-256、SHA-512；MD5 改用內建純 JS 實作（因為 Web Crypto API 沒有 MD5）。所有運算都在你的裝置上完成，不會送出任何資料。