![Created Byy SJ Dalore
17
The AES Cipher
Add round key
Substitute bytes
Shift rows
Mix columns
Add Round key
Substitute bytes
Shift rows
Mix columns
Add round key
Substitute bytes
Shift rows
Add round key
plaintext
Cipher text
key
W[4,7] W[36,39] W[40,43]
Round
1
Round
9](https://image.slidesharecdn.com/advancedencryptionstandardaes-231215190425-4fff97eb/85/Advanced-Encryption-Standard-AES-pdf-17-320.jpg)
![Created Byy SJ Dalore
22
The AES Inverse Cipher
Add round key
Inv. Shift rows
Inv. Sub bytes
Add round key
Inv. Mix Columns
Inv. Shift rows
Inv. Sub bytes
Add round key
Inv. Mix columns
Inv. Shift rows
Inv. Sub bytes
Add round key
ciphertext
plaintext
key
W[36,39] W[4,7] W[0,3]
Round
1
Round
9](https://image.slidesharecdn.com/advancedencryptionstandardaes-231215190425-4fff97eb/85/Advanced-Encryption-Standard-AES-pdf-22-320.jpg)
Advanced Encryption Standard (AES).pdf
- 1. Advanced Encryption Standard (AES) Securing the Digital World Created Byy SJ Dalore 1
- 2. Agenda Created Byy SJ Dalore 2 • Introduction to AES • History and Development • How AES Works • Strengths and Advantages • Practical Applications
- 3. Introduction to AES Created Byy SJ Dalore 3 Introduction to Cryptography
- 4. Created Byy SJ Dalore 4 Definition of AES AES, or the Advanced Encryption Standard, is a widely-used symmetric encryption algorithm that plays a crucial role in securing digital data. It was established as a federal standard for encryption by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES has since become a global encryption standard used to protect sensitive information in various applications, including secure communication, data storage, and more.
- 5. Created Byy SJ Dalore 5 Encryption What is Encryption Goal of Encryption • Encryption is the process of converting data or information into a secure and unreadable format, known as cipher text, to protect it from unauthorized access or interception. This transformation is done using an encryption algorithm and a secret encryption key. • encryption is a fundamental tool for safeguarding digital information, providing a strong defense against unauthorized access and ensuring the privacy and security of data in a variety of applications.
- 6. Examples of Encryption Algorithm Created Byy SJ Dalore 6 • Symmetric Encryption – AES, DES • Asymmetric Encryption (Public Key Encryption) – RSA, ECC • Hash Functions – SHA-256, MD5 • Message Digest (One-Way) Encryption – bcrypt, PBKDF2 • End-to-End Encryption (E2E) • File and Disk Encryption – BitLocker, File Vault, LUKS • Network Encryption (TLS/SSL) • Database Encryption • Homomorphic Encryption • Quantum Encryption - QKD • Transparent Data Encryption (TDE)
- 7. History and Development Created Byy SJ Dalore 7
- 8. Created Byy SJ Dalore 8 Background of AES 1970 DES used a fixed 56-bit key length, which was considered secure at the time but became increasingly vulnerable to brute- force attacks as computing power advanced. Data Encryption Standard (DES) NIST announced a competition, known as the Advanced Encryption Standard (AES) competition, in 1997, inviting the global cryptographic community to submit encryption algorithms for evaluation. Initiation of AES Development Rijndael was selected because it had the best combination of security, performance, efficiency, implementability and flexibility Selection of Rijndael AES was officially adopted as a federal standard for encryption by the U.S. government in 2001 through Federal Information Processing Standard (FIPS) 197. Adoption and Global Usage 1997 2000 2001
- 9. Created Byy SJ Dalore 9 AES VS DES AES DES • Uses symmetric-key encryption algorithms • Varieties of Key length – 128, 192, and 256 bits • Considered highly secure • Employs a complex algorithm that includes substitution, permutation, and mixing operations in multiple rounds • Uses symmetric-key encryption algorithms • Fix key length – 56 bits • Vulnerable to brute-force attacks • Simplicity of the algorithm contributed to its vulnerability over time.
- 10. How AES Works Created Byy SJ Dalore 10
- 11. How AES works Created Byy SJ Dalore 11 • Key Generation: AES requires a secret key for encryption and decryption. The key must be a specific length (128, 192, or 256 bits) depending on the chosen AES variant. Key generation is a crucial step, and the security of AES relies heavily on the strength of the secret key. • Data Division: The plaintext data to be encrypted is divided into fixed-size blocks. In AES, each block is 128 bits (16 bytes). • Initial Round: AES operates on each block through a series of rounds. In the initial round, the plaintext block is combined with the initial secret key. • Rounds: The number of rounds in AES depends on the key length: • 128-bit key: 10 rounds • 192-bit key: 12 rounds • 256-bit key: 14 rounds • In each round, a combination of substitution, permutation, and mixing operations is applied to the data using a round key derived from the original secret key. • Final Round: The final round is similar to the other rounds but lacks the "MixColumns" step, which is present in all previous rounds. • Output: After all the rounds are completed, you have the ciphertext, which is the encrypted data. • Decryption: To decrypt the ciphertext, the same AES algorithm is applied but in reverse, using the same secret key (or a derived key) and reversing the order of the round keys.
- 12. The AES Cipher • Block length is limited to 128 bit • The key size can be independently specified to 128, 192 or 256 bits Key size (words/bytes/bits) 4/16/128 6/24/192 8/32/256 Number of rounds 10 12 14 Expanded key size (words/byte) 44/176 52/208 60/240 12
- 13. The AES Cipher • Key received as input array of 4 rows and Nk columns • Nk = 4,6, or 8, parameter which depends key size • Input key is expanded into an array of 44/52/60 words of 32 bits each • 4 different words serve as a key for each round k0 k4 k8 k12 k1 k2 k3 k5 k6 k7 k9 k10 k11 k13 k14 k15 w0 w1 w2 …… w42 w43 13
- 14. The AES Cipher • Single 128 bit block as input • Copied to a State array with Nb columns (Nb=4) in0 in4 in8 in12 in1 in2 in3 in5 in6 in7 in9 in10 in11 in13 in14 in15 S00 S01 S02 S03 S10 S20 S30 S11 S21 S31 S12 S22 S32 S13 S23 S33 o0 o4 o8 o12 o1 o2 o3 o5 o6 o7 o9 o10 o11 o13 o14 o15 Input State array Output 14
- 15. The AES Cipher Created Byy SJ Dalore 15 • Number of rounds, Nr, depends on key size • Each round is a repetition of functions that perform a transformation over State array • Consists of 4 main functions: one permutation and three substitutions Substitute bytes, Shift rows, Mix columns, Add round key
- 16. The AES Cipher Created Byy SJ Dalore 16 • AddRoundKey() – round key is added to the State using XOR operation • MixColumns() – takes all the columns of the State and mixes their data, independently of one another, making use of arithmetic over GF(2^8) • ShiftRows() – processes the State by cyclically shifting the last three rows of the State by different offsets • SubBytes() – uses S-box to perform a byte-by-byte substitution of State
- 17. Created Byy SJ Dalore 17 The AES Cipher Add round key Substitute bytes Shift rows Mix columns Add Round key Substitute bytes Shift rows Mix columns Add round key Substitute bytes Shift rows Add round key plaintext Cipher text key W[4,7] W[36,39] W[40,43] Round 1 Round 9
- 18. EXAMPLE of CIPHER CODE Created Byy SJ Dalore 18
- 19. The AES Cipher Created Byy SJ Dalore 19 • Only Add round key makes use of the key • Other three functions are used for diffusion and confusion • Final round consists of only three stages
- 20. EXAMPLE OF INVERSE CIPHER CODE Created Byy SJ Dalore 20
- 21. The AES Inverse Cipher Created Byy SJ Dalore 21 • Decryption algorithm uses the expanded key in reverse order • All functions are easily reversible and their inverse form is used in decryption • Decryption algorithm is not identical to the encryption algorithm • Again, final round consists of only three stages
- 22. Created Byy SJ Dalore 22 The AES Inverse Cipher Add round key Inv. Shift rows Inv. Sub bytes Add round key Inv. Mix Columns Inv. Shift rows Inv. Sub bytes Add round key Inv. Mix columns Inv. Shift rows Inv. Sub bytes Add round key ciphertext plaintext key W[36,39] W[4,7] W[0,3] Round 1 Round 9
- 23. Strengths and Advantages Created Byy SJ Dalore 23
- 24. Strengths and Advantages Created Byy SJ Dalore 24 • Security: AES is considered secure against all known practical attacks when used with sufficiently long and random keys. Its strength lies in the complexity of its operations, which includes substitution, permutation, and key mixing, making it resistant to various cryptographic attacks like brute- force, differential, and linear attacks. • Key Length Options: AES supports key lengths of 128, 192, and 256 bits, allowing users to choose the level of security they need. Longer keys provide stronger encryption but may require more computational resources. • Efficiency: AES is computationally efficient and can be implemented in both software and hardware. It is optimized for modern computer architectures, making it practical for a wide range of applications, including encryption of data at rest and in transit.
- 25. Strengths and Advantages Created Byy SJ Dalore 25 • Standardization: AES is a widely recognized and standardized encryption algorithm, which enhances interoperability. It is used in various security protocols and applications, including SSL/TLS for secure web communication and file encryption tools. • Resistance to Attacks: AES has been extensively analyzed and reviewed by cryptographers worldwide. It has withstood years of scrutiny and has a strong security track record. It is known to be resistant to known cryptographic attacks, provided that the key is properly generated and managed. • Mathematically Sound: AES's security is based on well-established mathematical principles, which adds to its credibility and trustworthiness. It relies on a strong combination of substitution (S-boxes), permutation (P- boxes), and key mixing operations.
- 26. Strengths and Advantages Created Byy SJ Dalore 26 • Flexibility: AES can be used in various modes of operation (e.g., ECB, CBC, GCM) to suit different encryption requirements, such as confidentiality, integrity, and authenticated encryption. • Publicly Available: The AES algorithm is publicly available and free to use. This transparency allows security experts to review and analyze its design, which contributes to its overall security. • Global Adoption: AES is used worldwide by governments, financial institutions, businesses, and individuals for securing sensitive data. Its widespread adoption has led to extensive testing and validation. • Longevity: AES was selected as the encryption standard by the U.S. National Institute of Standards and Technology (NIST) in 2001, and it has remained a strong and trusted encryption choice for more than two decades.
- 27. Practical Applications Created Byy SJ Dalore 27
- 28. Practical Application Created Byy SJ Dalore 28 • AES (Advanced Encryption Standard) is widely used in various practical applications to secure data and communications. Here are some common practical applications for AES: 1. Data Encryption for File Storage 2. Secure Communication 3. Virtual Private Networks (VPNs) 4. Database Encryption 5. Secure Messaging Apps 6. Data Backup and Cloud Storage 7. Full Disk Encryption 8. Software and Application Security 9. Financial Transactions 10. IoT Security 11. Military and Government Communications 12. Secure Boot and Firmware Updates
- 29. Icebreaker Created Byy SJ Dalore 29 Head, Shoulder, Knees, Toes, Slippers
- 30. Q&A Created Byy SJ Dalore 30
- 31. Conclusion Created Byy SJ Dalore 31 Recap of the Lesson
- 32. Conclusion Created Byy SJ Dalore 32 • Encryption is a fundamental tool in information security, providing a robust defense against unauthorized access and data breaches. • We explored various types of encryption, from symmetric and asymmetric encryption to hashing and end-to-end encryption. • The choice of encryption method depends on factors like security requirements, performance, and specific application needs. • Leading encryption standards, such as AES and RSA, play a pivotal role in securing digital data across the globe. • Proper key management is crucial for the effective implementation of encryption and safeguarding encrypted data. • Encryption is a critical component of data protection, ensuring confidentiality, integrity, and privacy in the digital age.
- 33. Created Byy SJ Dalore 33 Thank You
- 34. Quiz Created Byy SJ Dalore 34
- 35. 1. What does AES stand for? Created Byy SJ Dalore 35 A) Advanced Encryption System B) Advanced Encryption Standard C) Algorithm for Encryption and Security D) Advanced Encoding System
- 36. 2. How many rounds of encryption does AES-128 have? Created Byy SJ Dalore 36 A) 10 rounds B) 12 rounds C) 14 rounds D) 16 rounds
- 37. 3. What is the key length of AES-192? Created Byy SJ Dalore 37 A) 64 bits B) 128 bits C) 192 bits D) 256 bits
- 38. 4. AES operates on blocks of how many bits at a time? Created Byy SJ Dalore 38 A) 64 bits B) 128 bits C) 256 bits D) 512 bits
- 39. 5. Which type of encryption does AES use? Created Byy SJ Dalore 39 A) Symmetric-key encryption B) Asymmetric encryption C) Hybrid encryption D) None of the above
- 40. 6. Who developed the Rijndael algorithm, which became AES? Created Byy SJ Dalore 40 A) Alan Turing B) Vincent Rijmen and Joan Daemen C) Ron Rivest D) Whitfield Diffie and Martin Hellman
- 41. 7. What is the maximum key length supported by AES? Created Byy SJ Dalore 41 A) 64 bits B) 128 bits C) 192 bits D) 256 bits
- 42. 8. What are the three standard key lengths for AES? Created Byy SJ Dalore 42 A) 64, 128, 192 bits B) 56, 128, 256 bits C) 64, 256, 512 bits D) 128, 192, 256 bits
- 43. 9. Which government agency initially selected AES as the encryption standard in the United States? Created Byy SJ Dalore 43 A) FBI (Federal Bureau of Investigation) B) NSA (National Security Agency) C) CIA (Central Intelligence Agency) D) DEA (Drug Enforcement Administration)
- 44. 10. AES is considered secure against which type of attack, which tries all possible keys? Created Byy SJ Dalore 44 A) Birthday attack B) Rainbow table attack C) Brute-force attack D) Man-in-the-middle attack