Network Security Secure hashing algorithm or SHA algorithm and itβs various versions network secure.
Hereβs a complete guide to the Secure Hashing Algorithm (SHA), including its versions, uses in network security, and importance in cryptography β especially relevant for GATE CSE, Cybersecurity, Networking, and Computer Science Engineering students.
Contents
- 1 What is SHA (Secure Hashing Algorithm)?
- 2 Why is SHA Important in Network Security?
- 3 SHA Versions Overview
- 4 SHA-1 (Insecure) β Avoid using!
- 5 SHA-2 Family (Secure, Recommended)
- 6 SHA-3 (New Standard)
- 7 How Hashing Works (Simple Illustration)
- 8 Properties of a Good Hash Function
- 9 Summary Table
- 10 SHA in Exams & Interviews
- 11 Want More?
- 11.1 Network Security Secure hashing algorithm or SHA algorithm and itβs various versions network secure.
- 11.2 CRYPTOGRAPHIC SECURE HASH ALGORITHM WITH β¦
- 11.3 A REVIEW OF VARIOUS SECURE HASH ALGORITHMS β¦
- 11.4 Hashing for Message Authentication Lecture Notes on β β¦
- 11.5 cryptography and network security lecture notes
What is SHA (Secure Hashing Algorithm)?
SHA is a family of cryptographic hash functions designed to ensure data integrity by generating a fixed-size hash (or digest) from input data (message).
Hash Function: Takes an input (of any size) β produces a fixed-length hash value.
Why is SHA Important in Network Security?
Data Integrity: Ensures that the data was not tampered with. Password Storage: Stores passwords as hash values. Digital Signatures: Used in SSL/TLS, HTTPS. Blockchain & Cryptography: SHA-256 powers Bitcoin mining.
SHA Versions Overview
Version | Output Size | Year Introduced | Status | Use Cases |
---|---|---|---|---|
SHA-0 | 160 bits | 1993 | Obsolete | Weak security |
SHA-1 | 160 bits | 1995 | Broken/Retired | Was widely used (SSL, Git, etc.) |
SHA-2 | 224/256/384/512 bits | 2001 | Secure | Widely used in modern cryptography |
SHA-3 | 224/256/384/512 bits | 2025 | Secure | Backup standard (based on Keccak) |
SHA-1 (Insecure) β Avoid using!
Used in SSL certificates, Git, older systems. Broken by collision attacks (Googleβs SHAttered attack). Deprecated by most browsers & organizations.
SHA-2 Family (Secure, Recommended)
Includes:
SHA-224
SHA-256
(most popular)SHA-384
SHA-512
SHA-256:
- Most widely used
- Fixed 256-bit output
- Secure and collision-resistant
- HTTPS
- Bitcoin and blockchain
- JWT (JSON Web Tokens)
- Software verification
SHA-3 (New Standard)
- Based on Keccak algorithm (not MerkleβDamgΓ₯rd like SHA-1/2)
- More resistant to length-extension attacks
- Useful for post-quantum cryptography and IoT devices
How Hashing Works (Simple Illustration)
Input Message β SHA Algorithm β Unique Hash Code
Example:
Input: "hello"
SHA-256 Output:
2cf24dba5fb0a... (64 hex characters = 256 bits)
Properties of a Good Hash Function
- Deterministic β Same input β same output
- Fast β Efficient to compute
- Irreversible β Canβt reverse to get input
- Collision-resistant β No two inputs β same hash
- Avalanche effect β Tiny change β big hash change
Summary Table
Feature | SHA-1 | SHA-2 (256/512) | SHA-3 |
---|---|---|---|
Output Length | 160 bits | 256β512 bits | 256β512 bits |
Security | Weak (Broken) | Strong | Strong (Keccak) |
Collision Resistance | Low | High | Very High |
Applications | Legacy Systems | Modern Crypto | Advanced/Research |
SHA in Exams & Interviews
GATE, UGC NET, and ISRO exams often ask:
- Hash output lengths
- Which version is secure/insecure
- Hash function properties
- Usage in SSL, Blockchain, etc.
Want More?
I can provide:
SHA algorithm source code (Python/C++) Comparison chart (PDF) Practice MCQs (GATE-style) Real-world use case analysis (blockchain, auth)
Would you like a diagram, code example, or quiz based on SHA?