MODULE 06 · AUTHENTICATION & SECURITY

Hashing

A one-way transformation that turns input data into a fixed-length value.

01 · What is it?

Hashing transforms data into a hash value that is designed to be difficult to reverse.

Systems can compare hash values without keeping the original input in the same form.

Think of hashing like making a tamper-evident fingerprint for a document.

Input

→

Hash Function

→

Hash Value

→

Compare

Protects Password Storage

Systems can store a password hash instead of the password itself.

Checks Integrity

A changed input produces a different value.

Supports Lookup

Hash values help software compare known data efficiently.

Hashing is used for password storage, file integrity checks, and content identifiers.

A login system hashes the password entered by a user and compares it with the stored password hash.

A secure password system uses a password-specific hashing algorithm and a unique salt.

Password Input→Hash Function→Stored Hash→Comparison

Designed as a one-way transformation.

Designed to be reversed with a key.

Changes representation for transport or storage.

ENGLISH TERM	中文	SIMPLE ENGLISH	中文小白理解
Hashing	哈希	A one-way transformation into a hash value.	把数据转换成哈希值的一种单向处理。
Hash Value	哈希值	The output produced by a hash function.	哈希函数处理后得到的结果。
Salt	盐值	Extra unique data added before password hashing.	在密码哈希前加入的一段独特额外数据。
Integrity	完整性	Confidence that data has not changed.	确认数据没有被悄悄修改。

Hashing is designed to create a comparable fingerprint without exposing the original input.