===== crypto/sha256 =====

==== What is it? ====
`crypto/sha256` provides the SHA-256 cryptographic hash function.

==== What is it used for? ====
  * Generate a fixed-length digest (hash) from data.
  * Verify integrity (data has not changed).
  * Used in signatures, checksums, and many security protocols.

==== Example (Sum256) ====
<code go>
package main

import (
    "crypto/sha256"
    "fmt"
)

func main() {
    sum := sha256.Sum256([]byte("hello"))
    fmt.Printf("%x\n", sum)
}
</code>

==== Notes ====
  * SHA-256 is a hash, not encryption.
  * For password hashing, use `bcrypt/scrypt/argon2` (do not use plain SHA-256).

==== Related pages ====
  * [[go:crypto:md5|crypto/md5]]
  * [[go:crypto:hmac|crypto/hmac]]
  * [[go:crypto:sha512|crypto/sha512]]

==== Hard words (English) ====
  * **digest** /ˈdaɪdʒest/: bản băm (kết quả hash)
  * **integrity** /ɪnˈteɡrɪti/: tính toàn vẹn
  * **encryption** /ɪnˈkrɪpʃən/: mã hoá
  * **checksum** /ˈtʃeksʌm/: mã kiểm tra