AES - Advanced Encryption Standard

What is AES?

AES stands for Advanced Encryption Standard. It’s a symmetric encryption algorithm used to securely encrypt and decrypt data. AES is widely used to protect sensitive information in files, emails, network communications, and databases.

Why is AES useful?

• Data privacy and security are critical today. AES helps by: * Encrypting data so unauthorized users can’t read it. * Ensuring confidentiality during storage or transmission. * Providing fast, strong encryption resistant to attacks. * Without AES, sensitive data like passwords and financial info could be easily intercepted.

How it works?

• Key generation – A secret key (128, 192, or 256 bits) is chosen, shared by sender and receiver.

• Encryption – Plaintext is transformed into ciphertext using AES and the key.

• Transmission/Storage – Ciphertext is sent or stored securely.

• Decryption – The receiver uses the key to restore plaintext from ciphertext.

Where is AES used?

• Secure websites (HTTPS) encrypt web traffic.

• Wi-Fi security (WPA2/WPA3) uses AES.

• File encryption tools (BitLocker, VeraCrypt, 7-Zip).

• Messaging apps with end-to-end encryption (Signal, WhatsApp).

• VPNs and secure tunnels to protect data in transit.

Which OSI layer does this protocol belong to?

• AES operates primarily at the Presentation Layer (Layer 6).

• Encryption/decryption transform data before it reaches the application.

• It ensures confidentiality and proper formatting for application consumption.

Topics in this section,

• Learnings in this section

• Terminology

• Version Info

• AES Version&RFC Details

• AES Basic Setup on Ubuntu using IPv4

• AES Basic Setup on Ubuntu using IPv6

• AES Protocol Packet Details

• AES Usecases

• AES Basic Features

• AES Feature : Symmetric Key Cipher

• AES Feature : Block Cipher

• AES Feature : Key Sizes

• AES Feature : Number of Rounds

• AES Feature : Substitution-Permutation Network (SPN)

• AES Feature : Fast and Efficient

• AES Feature : Strong Security

• AES Feature : Widely Adopted

• AES Feature : Flexible Modes of Operation

• Reference links

Learnings in this section

• In this section, you are going to learn

Terminology

• Terminology

Version Info

• Version Info

AES Version&RFC Details

AES Version	AES Number	Year	Core Idea / Contribution
AES (Rijndael)	FIPS PUB 197	2001	Standardized the Rijndael block cipher as AES. Supports 128-bit block size with 128, 192, or 256-bit keys. Selected after a 5-year public competition by NIST.
AES Update	FIPS PUB 197 (Revised)	2023	Editorial update onlyno technical changes. Improved formatting, added diagrams, clarified definitions.
AES in Internet Protocols	RFC 3602 (AES-CBC), RFC 5116 (AES-GCM)	2003 / 2008	Specifies how AES is used in IPsec and other protocols. AES-CBC and AES-GCM modes defined for secure communication.

AES Basic Setup on Ubuntu using IPv4

• Setup

AES Basic Setup on Ubuntu using IPv6

• Setup

AES Protocol Packet Details

AES Encryption Packet

S.No	Protocol Packets	Description	Size(Bytes)
1	AES Encryption Packet	Used to encrypt a 128-bit block of plaintext using a symmetric key.	496 / 536 / 576
	Plaintext Block	The original data to be encrypted.	16
	Key	Secret key used for encryption. Can be 128, 192, or 256 bits.	16 / 24 / 32
	Initialization Vector (IV)	Used in modes like CBC to ensure randomness. Not used in ECB mode.	16
	Round Keys	Keys derived from the original key for each AES round.	176 / 208 / 240
	State Matrix	Internal 44 byte matrix used during AES transformations.	16
	S-Box	Substitution box used in the SubBytes step.	256
	Ciphertext Block	The encrypted output after all AES rounds.	16

AES Decryption Packet

S.No	Protocol Packets	Description	Size(Bytes)
2	AES Decryption Packet	Used to decrypt a 128-bit ciphertext block using the same symmetric key.	496 / 536 / 576
	Ciphertext Block	The encrypted data to be decrypted.	16
	Key	Same symmetric key used during encryption.	16 / 24 / 32
	Initialization Vector (IV)	Required for modes like CBC to reverse the XOR step.	16
	Round Keys	Derived from the key, used in reverse order during decryption.	176 / 208 / 240
	State Matrix	Internal 44 byte matrix used during AES transformations.	16
	Inverse S-Box	Used in the InvSubBytes step during decryption.	256
	Plaintext Block	The original data recovered after decryption.	16

AES Usecases

S.no	Use Case	Description
1	Secure Web Communication	AES is used in HTTPS (SSL/TLS) to encrypt data between browsers and servers.
2	Wi-Fi Security	AES is the core encryption algorithm in WPA2 and WPA3 for protecting wireless networks.
3	File Encryption	Tools like BitLocker, VeraCrypt, and 7-Zip use AES to encrypt files and drives.
4	Messaging Apps	End-to-end encryption in apps like WhatsApp, Signal, and Telegram uses AES.
5	VPNs	AES encrypts data in transit to ensure privacy and security over public networks.
6	Mobile Device Encryption	iOS and Android use AES to encrypt user data stored on the device.
7	Database Encryption	AES is used to encrypt sensitive fields or entire databases (e.g., in SQL Server, Oracle).
8	Cloud Storage	Services like Google Drive and Dropbox use AES to encrypt files stored in the cloud.
9	Payment Systems	AES secures transaction data in systems like EMV chip cards and mobile wallets.
10	Military & Government Use	AES-256 is approved for encrypting classified and top-secret information.

AES Basic Features

S.no	Feature	Description
1	Symmetric Key Cipher	Uses the same key for both encryption and decryption.
2	Block Cipher	Operates on fixed-size blocks of data (128 bits).
3	Key Sizes	Supports 128, 192, and 256-bit keys for varying levels of security.
4	Number of Rounds	10, 12, or 14 rounds depending on key size.
5	SubstitutionPermutation Network (SPN)	Uses multiple rounds of substitution and permutation for encryption.
6	Fast and Efficient	Designed for high performance in both hardware and software.
7	Strong Security	Resistant to known attacks like brute-force, differential, and linear cryptanalysis.
8	Widely Adopted	Used globally in government, finance, and consumer applications.
9	Flexible Modes of Operation	Supports ECB, CBC, CFB, OFB, GCM, etc., for different use cases.

AES Feature : Symmetric Key Cipher

Symmetric Key Cipher - Testcases

#	Test Case	Description	Expected Result
1	Encrypt with AES-128	Use 128-bit key for encryption	Ciphertext generated
2	Decrypt with AES-128	Use same 128-bit key for decryption	Original plaintext recovered
3	Encrypt with AES-192	Use 192-bit key for encryption	Ciphertext generated
4	Decrypt with AES-192	Use same 192-bit key for decryption	Original plaintext recovered
5	Encrypt with AES-256	Use 256-bit key for encryption	Ciphertext generated
6	Decrypt with AES-256	Use same 256-bit key for decryption	Original plaintext recovered
7	Encrypt and Decrypt with Same Key	Use same key for both operations	Data integrity maintained
8	Encrypt and Decrypt with Wrong Key	Use different key for decryption	Decryption fails or produces garbage
9	Encrypt Empty String	Encrypt an empty string	Valid ciphertext generated
10	Decrypt Empty Ciphertext	Decrypt empty ciphertext	Empty string returned
11	Encrypt Short Text	Encrypt short plaintext	Ciphertext generated
12	Encrypt Long Text	Encrypt large plaintext	Ciphertext generated
13	Encrypt Binary Data	Encrypt binary input	Ciphertext generated
14	Decrypt Binary Ciphertext	Decrypt binary ciphertext	Original binary data recovered
15	Use Hex Key	Use hexadecimal key for AES	Encryption succeeds
16	Use Base64 Key	Use base64-encoded key	Encryption succeeds
17	Use Random Key	Generate random symmetric key	Encryption and decryption succeed
18	Use Static Key	Use fixed key	Consistent results
19	Use Weak Key	Use simple key (e.g., all zeros)	Encryption works but insecure
20	Use Strong Key	Use high-entropy key	Encryption secure
21	Use Key with Wrong Length	Use 100-bit key	Error or rejection
22	Use Key Padding	Pad key to valid length	Encryption succeeds
23	Use ECB Mode	Encrypt using AES in ECB mode	Ciphertext generated (less secure)
24	Use CBC Mode	Encrypt using AES in CBC mode	Ciphertext generated with IV
25	Use CFB Mode	Encrypt using AES in CFB mode	Ciphertext generated
26	Use OFB Mode	Encrypt using AES in OFB mode	Ciphertext generated
27	Use CTR Mode	Encrypt using AES in CTR mode	Ciphertext generated
28	Use GCM Mode	Encrypt using AES in GCM mode	Ciphertext and tag generated
29	Use IV with CBC Mode	Provide initialization vector	Encryption succeeds
30	Use Same IV Twice	Reuse IV in CBC mode	Encryption succeeds but insecure
31	Use Different IVs	Use different IVs for same plaintext	Different ciphertexts generated
32	Encrypt with Padding	Use PKCS#7 padding	Ciphertext generated
33	Decrypt with Padding	Remove padding after decryption	Original plaintext recovered
34	Encrypt Without Padding	Use plaintext with block size multiple	Ciphertext generated
35	Encrypt Non-Block-Aligned Data	Use data not aligned to block size	Padding applied
36	Encrypt with Hardware Support	Use AES-NI instructions	Fast encryption
37	Encrypt with Software Library	Use OpenSSL or PyCrypto	Encryption succeeds
38	Encrypt with Custom Implementation	Use custom AES implementation	Encryption succeeds if correct
39	Encrypt with Key Rotation	Rotate keys periodically	Encryption remains secure
40	Encrypt with Key Expiry	Use expired key	Encryption fails or flagged
41	Encrypt with Key Management System	Retrieve key from KMS	Encryption succeeds
42	Encrypt with Secure Element	Use secure element for key storage	Encryption succeeds
43	Encrypt with TPM	Use Trusted Platform Module	Encryption succeeds
44	Encrypt with HSM	Use Hardware Security Module	Encryption succeeds
45	Encrypt with Compliance Logging	Enable logging for audit	Logs show key usage
46	Encrypt with SIEM Integration	Send logs to SIEM	Events visible in SIEM
47	Encrypt with Access Control	Restrict key usage by role	Unauthorized access blocked
48	Encrypt with Key Backup	Use backup key if primary fails	Encryption continues
49	Encrypt with Key Revocation	Revoke compromised key	Key no longer usable
50	Encrypt with Key Derivation	Derive key from password using PBKDF2	Encryption succeeds with derived key

AES Feature : Block Cipher

Block Cipher - Testcases

#	Test Case	Description	Expected Result
1	Encrypt 128-bit block	Encrypt exactly 128-bit plaintext	Ciphertext generated
2	Encrypt 256-bit block	Encrypt two 128-bit blocks	Two ciphertext blocks generated
3	Encrypt 64-bit block	Encrypt half-block with padding	One ciphertext block generated
4	Encrypt 129-bit block	Encrypt slightly over one block	Two ciphertext blocks generated
5	Encrypt 0-bit block	Encrypt empty input	Empty ciphertext
6	Encrypt 1024-bit block	Encrypt 8 blocks	8 ciphertext blocks generated
7	Encrypt with PKCS#7 padding	Pad to 128-bit block size	Valid ciphertext
8	Encrypt with ISO/IEC 7816-4 padding	Use alternate padding scheme	Valid ciphertext
9	Encrypt with no padding	Input is multiple of 128 bits	Ciphertext generated
10	Encrypt with incorrect padding	Input not padded correctly	Error or incorrect decryption
11	Decrypt 128-bit block	Decrypt one block	Original plaintext recovered
12	Decrypt 256-bit block	Decrypt two blocks	Original plaintext recovered
13	Decrypt with wrong padding	Padding mismatch	Error or garbage output
14	Encrypt with ECB mode	Block-by-block encryption	Identical blocks produce same ciphertext
15	Encrypt with CBC mode	Chained block encryption	Ciphertext varies with IV
16	Encrypt with CFB mode	Stream-like block encryption	Ciphertext generated
17	Encrypt with OFB mode	Output feedback mode	Ciphertext generated
18	Encrypt with CTR mode	Counter mode	Ciphertext generated
19	Encrypt with GCM mode	Authenticated encryption	Ciphertext and tag generated
20	Encrypt with same plaintext blocks	ECB mode	Identical ciphertext blocks
21	Encrypt with different IVs	CBC mode	Different ciphertexts
22	Encrypt with reused IV	CBC mode	Ciphertext same, insecure
23	Encrypt with IV = 0	CBC mode	Ciphertext generated, insecure
24	Encrypt with random IV	CBC mode	Ciphertext varies
25	Encrypt with IV length 128 bits	Invalid IV	Error or rejection
26	Encrypt with IV = 128 bits	Valid IV	Encryption succeeds
27	Encrypt with block-aligned data	No padding needed	Ciphertext generated
28	Encrypt with non-aligned data	Padding applied	Ciphertext generated
29	Encrypt with UTF-8 text	Multibyte characters	Ciphertext generated
30	Encrypt with ASCII text	Single-byte characters	Ciphertext generated
31	Encrypt with binary data	Raw bytes	Ciphertext generated
32	Encrypt with JSON data	Structured text	Ciphertext generated
33	Encrypt with XML data	Structured text	Ciphertext generated
34	Encrypt with image data	Binary file	Ciphertext generated
35	Encrypt with audio data	Binary file	Ciphertext generated
36	Encrypt with video data	Large binary file	Ciphertext generated
37	Encrypt with compressed data	ZIP or GZIP	Ciphertext generated
38	Encrypt with encrypted input	Double encryption	Ciphertext generated
39	Encrypt with corrupted block	Modify one block	Decryption fails or partial recovery
40	Encrypt with tampered IV	Modify IV	Decryption fails or incorrect
41	Encrypt with block chaining	CBC mode	Each block depends on previous
42	Encrypt with block independence	ECB mode	Each block independent
43	Encrypt with block size 128 bits	Invalid block size	Error or rejection
44	Encrypt with 128-bit aligned file	No padding needed	Ciphertext generated
45	Encrypt with 1MB file	Multiple blocks	Ciphertext generated
46	Encrypt with 1GB file	Large input	Ciphertext generated
47	Encrypt with streaming input	Block-by-block processing	Ciphertext generated
48	Encrypt with block corruption	Flip bits in ciphertext	Decryption fails
49	Encrypt with block replay	Replay old ciphertext block	Potential vulnerability
50	Encrypt with block reordering	Change block order	Decryption fails or incorrect

AES Feature : Key Sizes

Key sizes - Testcases

#	Test Case	Description	Expected Result
1	Encrypt with 128-bit key	Use 16-byte key	Ciphertext generated
2	Encrypt with 192-bit key	Use 24-byte key	Ciphertext generated
3	Encrypt with 256-bit key	Use 32-byte key	Ciphertext generated
4	Decrypt with 128-bit key	Use same 128-bit key	Plaintext recovered
5	Decrypt with 192-bit key	Use same 192-bit key	Plaintext recovered
6	Decrypt with 256-bit key	Use same 256-bit key	Plaintext recovered
7	Encrypt with incorrect key size	Use 100-bit key	Error or rejection
8	Encrypt with oversized key	Use 512-bit key	Error or rejection
9	Encrypt with under-sized key	Use 64-bit key	Error or rejection
10	Encrypt with padded key	Pad to valid size	Encryption succeeds
11	Encrypt with hex 128-bit key	Use hex string	Ciphertext generated
12	Encrypt with hex 192-bit key	Use hex string	Ciphertext generated
13	Encrypt with hex 256-bit key	Use hex string	Ciphertext generated
14	Encrypt with base64 128-bit key	Use base64 string	Ciphertext generated
15	Encrypt with base64 192-bit key	Use base64 string	Ciphertext generated
16	Encrypt with base64 256-bit key	Use base64 string	Ciphertext generated
17	Encrypt with random 128-bit key	Generate random key	Ciphertext generated
18	Encrypt with random 192-bit key	Generate random key	Ciphertext generated
19	Encrypt with random 256-bit key	Generate random key	Ciphertext generated
20	Encrypt with static 128-bit key	Use fixed key	Consistent ciphertext
21	Encrypt with static 192-bit key	Use fixed key	Consistent ciphertext
22	Encrypt with static 256-bit key	Use fixed key	Consistent ciphertext
23	Encrypt with weak 128-bit key	All zeros	Works but insecure
24	Encrypt with weak 192-bit key	All ones	Works but insecure
25	Encrypt with weak 256-bit key	Repeating pattern	Works but insecure
26	Encrypt with strong 128-bit key	High entropy	Secure encryption
27	Encrypt with strong 192-bit key	High entropy	Secure encryption
28	Encrypt with strong 256-bit key	High entropy	Secure encryption
29	Encrypt with derived 128-bit key	Use PBKDF2	Ciphertext generated
30	Encrypt with derived 192-bit key	Use PBKDF2	Ciphertext generated
31	Encrypt with derived 256-bit key	Use PBKDF2	Ciphertext generated
32	Encrypt with key rotation	Rotate 128-bit key	Encryption remains secure
33	Encrypt with key rotation	Rotate 256-bit key	Encryption remains secure
34	Encrypt with expired key	Key marked expired	Encryption fails or flagged
35	Encrypt with revoked key	Key revoked	Encryption fails
36	Encrypt with key from KMS	Retrieve 128-bit key	Encryption succeeds
37	Encrypt with key from HSM	Use 256-bit key	Encryption succeeds
38	Encrypt with TPM key	Use 192-bit key	Encryption succeeds
39	Encrypt with secure element key	Use 128-bit key	Encryption succeeds
40	Encrypt with access-controlled key	Role-based access	Unauthorized blocked
41	Encrypt with backup key	Use backup 256-bit key	Encryption continues
42	Encrypt with key logging	Log 128-bit key usage	Logs generated
43	Encrypt with SIEM integration	Log 192-bit key usage	Events visible
44	Encrypt with compliance policy	Use 256-bit key	Policy enforced
45	Encrypt with FIPS-compliant key	Use validated key	Encryption succeeds
46	Encrypt with AES-NI and 128-bit key	Hardware acceleration	Fast encryption
47	Encrypt with OpenSSL and 192-bit key	Software library	Encryption succeeds
48	Encrypt with PyCrypto and 256-bit key	Software library	Encryption succeeds
49	Encrypt with custom AES and 128-bit key	Custom implementation	Works if correct
50	Encrypt with mismatched key size	Encrypt with 128-bit, decrypt with 256-bit	Decryption fails

AES Feature : Number of Rounds

Number of Rounds - Testcases

#	Test Case	Description	Expected Result
1	AES-128 Rounds	Use 128-bit key	10 rounds executed
2	AES-192 Rounds	Use 192-bit key	12 rounds executed
3	AES-256 Rounds	Use 256-bit key	14 rounds executed
4	AES-128 Round Count Check	Verify round count	10 rounds confirmed
5	AES-192 Round Count Check	Verify round count	12 rounds confirmed
6	AES-256 Round Count Check	Verify round count	14 rounds confirmed
7	AES-128 Round Key Generation	Generate round keys	11 round keys generated
8	AES-192 Round Key Generation	Generate round keys	13 round keys generated
9	AES-256 Round Key Generation	Generate round keys	15 round keys generated
10	AES-128 Final Round	Check last round	No MixColumns applied
11	AES-192 Final Round	Check last round	No MixColumns applied
12	AES-256 Final Round	Check last round	No MixColumns applied
13	AES-128 Round Timing	Measure time per round	Consistent timing
14	AES-192 Round Timing	Measure time per round	Slightly longer
15	AES-256 Round Timing	Measure time per round	Longest
16	AES-128 Round SubBytes	Validate SubBytes step	Correct substitution
17	AES-192 Round ShiftRows	Validate ShiftRows step	Correct shifting
18	AES-256 Round MixColumns	Validate MixColumns step	Correct mixing
19	AES-128 Round AddRoundKey	Validate key addition	XOR with round key
20	AES-192 Round Key Expansion	Validate key schedule	Correct keys derived
21	AES-256 Round Key Expansion	Validate key schedule	Correct keys derived
22	AES-128 Round Order	Check operation sequence	SubBytes ShiftRows MixColumns AddRoundKey
23	AES-192 Round Order	Check operation sequence	Same as above
24	AES-256 Round Order	Check operation sequence	Same as above
25	AES-128 Round Integrity	Tamper with round	Decryption fails
26	AES-192 Round Integrity	Tamper with round	Decryption fails
27	AES-256 Round Integrity	Tamper with round	Decryption fails
28	AES-128 Round Debug	Log each round	10 rounds logged
29	AES-192 Round Debug	Log each round	12 rounds logged
30	AES-256 Round Debug	Log each round	14 rounds logged
31	AES-128 Round Reversal	Decrypt step-by-step	Plaintext recovered
32	AES-192 Round Reversal	Decrypt step-by-step	Plaintext recovered
33	AES-256 Round Reversal	Decrypt step-by-step	Plaintext recovered
34	AES-128 Round Fault Injection	Inject fault in round	Output corrupted
35	AES-192 Round Fault Injection	Inject fault in round	Output corrupted
36	AES-256 Round Fault Injection	Inject fault in round	Output corrupted
37	AES-128 Round Skipping	Skip a round	Decryption fails
38	AES-192 Round Skipping	Skip a round	Decryption fails
39	AES-256 Round Skipping	Skip a round	Decryption fails
40	AES-128 Round Duplication	Duplicate a round	Decryption fails
41	AES-192 Round Duplication	Duplicate a round	Decryption fails
42	AES-256 Round Duplication	Duplicate a round	Decryption fails
43	AES-128 Round Count Mismatch	Use wrong round count	Decryption fails
44	AES-192 Round Count Mismatch	Use wrong round count	Decryption fails
45	AES-256 Round Count Mismatch	Use wrong round count	Decryption fails
46	AES-128 Round Key Mismatch	Use wrong round key	Decryption fails
47	AES-192 Round Key Mismatch	Use wrong round key	Decryption fails
48	AES-256 Round Key Mismatch	Use wrong round key	Decryption fails
49	AES-128 Round Visualization	Visualize each round	10 rounds shown
50	AES-256 Round Visualization	Visualize each round	14 rounds shown

AES Feature : Substitution-Permutation Network (SPN)

Substitution-Permutation Network (SPN) - Testcases

#	Test Case	Description	Expected Result
1	Apply SubBytes	Substitute bytes using S-box	Bytes transformed
2	Apply ShiftRows	Permute rows of state matrix	Rows shifted
3	Apply MixColumns	Mix columns using matrix multiplication	Columns transformed
4	Apply AddRoundKey	XOR state with round key	State updated
5	SPN Round Execution	Execute full round	State transformed
6	SPN Initial Round	Apply AddRoundKey only	Initial transformation
7	SPN Final Round	Skip MixColumns	Final transformation
8	SPN with AES-128	10 rounds of SPN	Encryption succeeds
9	SPN with AES-192	12 rounds of SPN	Encryption succeeds
10	SPN with AES-256	14 rounds of SPN	Encryption succeeds
11	SPN Byte Substitution	Validate S-box mapping	Correct substitution
12	SPN Byte Inversion	Use inverse S-box	Correct decryption
13	SPN Row Permutation	Validate ShiftRows	Correct row shift
14	SPN Column Mixing	Validate MixColumns	Correct column mix
15	SPN Key Mixing	Validate AddRoundKey	Correct XOR operation
16	SPN Round Integrity	Tamper with round	Decryption fails
17	SPN Round Skipping	Skip substitution	Decryption fails
18	SPN Round Duplication	Duplicate permutation	Decryption fails
19	SPN Round Reordering	Change order of steps	Decryption fails
20	SPN Round Logging	Log each transformation	All steps visible
21	SPN Round Visualization	Visualize state matrix	Changes per round shown
22	SPN Fault Injection	Inject fault in substitution	Output corrupted
23	SPN Fault Injection	Inject fault in permutation	Output corrupted
24	SPN Fault Injection	Inject fault in key mixing	Output corrupted
25	SPN Round Count Check	Count SPN rounds	Matches AES spec
26	SPN Round Key Expansion	Generate round keys	Keys match round count
27	SPN Round Key Mismatch	Use wrong key	Decryption fails
28	SPN Round Key Reuse	Reuse key across rounds	Insecure encryption
29	SPN Round Key Rotation	Rotate keys	Encryption remains secure
30	SPN Round Key Derivation	Derive keys from master key	Keys generated correctly
31	SPN with ECB Mode	No IV used	SPN applied per block
32	SPN with CBC Mode	IV used	SPN applied with chaining
33	SPN with CFB Mode	Feedback used	SPN applied to stream
34	SPN with OFB Mode	Output feedback used	SPN applied to stream
35	SPN with CTR Mode	Counter used	SPN applied to counter blocks
36	SPN with GCM Mode	Authenticated encryption	SPN applied with tag
37	SPN with corrupted input	Modify plaintext	Output differs
38	SPN with corrupted output	Modify ciphertext	Decryption fails
39	SPN with corrupted S-box	Use wrong substitution table	Decryption fails
40	SPN with corrupted permutation	Use wrong ShiftRows	Decryption fails
41	SPN with corrupted MixColumns	Use wrong matrix	Decryption fails
42	SPN with corrupted round key	Use wrong key	Decryption fails
43	SPN with custom S-box	Use alternate substitution	Encryption works if reversible
44	SPN with custom permutation	Use alternate row shift	Encryption works if reversible
45	SPN with custom MixColumns	Use alternate matrix	Encryption works if reversible
46	SPN with custom round structure	Change order of steps	Encryption works if reversible
47	SPN with reduced rounds	Use fewer rounds	Encryption weaker
48	SPN with increased rounds	Use more rounds	Encryption stronger
49	SPN with round profiling	Measure time per step	Performance analyzed
50	SPN with round auditing	Log transformations	Audit trail available

AES Feature : Fast and Efficient

Fast and Efficient - Testcases

#	Test Case	Description	Expected Result
1	Encrypt with AES-NI	Use hardware acceleration	Fast encryption
2	Decrypt with AES-NI	Use hardware acceleration	Fast decryption
3	Encrypt with OpenSSL	Use optimized software library	Fast encryption
4	Decrypt with OpenSSL	Use optimized software library	Fast decryption
5	Encrypt 1KB data	Measure time	< 1 ms (typical)
6	Encrypt 1MB data	Measure time	Fast performance
7	Encrypt 1GB data	Measure time	Efficient throughput
8	Encrypt on ARM CPU	Test on mobile processor	Efficient performance
9	Encrypt on Intel CPU	Test on desktop processor	High speed
10	Encrypt on GPU	Use GPU acceleration	High throughput
11	Encrypt on FPGA	Use hardware implementation	Very fast
12	Encrypt on ASIC	Use custom chip	Maximum efficiency
13	Encrypt with multithreading	Parallel processing	Speedup observed
14	Encrypt with SIMD	Use vector instructions	Performance boost
15	Encrypt with pipelining	Hardware pipeline	High throughput
16	Encrypt with low memory	Constrained environment	Still efficient
17	Encrypt on embedded system	IoT device	Acceptable speed
18	Encrypt on smartphone	Mobile device	Fast encryption
19	Encrypt on browser	JavaScript/WebCrypto	Fast and responsive
20	Encrypt with Python	Use PyCryptodome	Reasonable speed
21	Encrypt with C	Use native implementation	Very fast
22	Encrypt with Rust	Use safe and fast code	High performance
23	Encrypt with Go	Use Go crypto library	Efficient
24	Encrypt with Java	Use JCE	Fast encryption
25	Encrypt with .NET	Use System.Security.Cryptography	Fast encryption
26	Encrypt with Node.js	Use crypto module	Fast encryption
27	Encrypt with WebAssembly	Run in browser	Near-native speed
28	Encrypt with low CPU usage	Monitor CPU	Efficient resource use
29	Encrypt with low power	Measure energy	Power-efficient
30	Encrypt with low latency	Measure delay	Minimal latency
31	Encrypt with high throughput	Measure MB/s	High data rate
32	Encrypt with low overhead	Measure system load	Minimal impact
33	Encrypt with real-time input	Stream data	No lag
34	Encrypt with batch input	Process large files	Efficient
35	Encrypt with concurrent users	Multi-session	Scales well
36	Encrypt with cloud function	Serverless	Fast execution
37	Encrypt with Docker	Containerized app	No performance loss
38	Encrypt with Kubernetes	Scalable deployment	Efficient under load
39	Encrypt with load balancer	Distribute load	Maintains speed
40	Encrypt with caching	Reuse results	Faster response
41	Encrypt with precomputed keys	Avoid key expansion	Faster rounds
42	Encrypt with optimized S-box	Fast substitution	Improved speed
43	Encrypt with lookup tables	Precomputed values	Faster operations
44	Encrypt with minimal code	Lightweight implementation	Fast execution
45	Encrypt with optimized compiler	Use -O3 flag	Faster binary
46	Encrypt with JIT compilation	Runtime optimization	Fast execution
47	Encrypt with benchmarking	Compare libraries	AES is fastest
48	Encrypt with profiling	Identify bottlenecks	AES shows efficiency
49	Encrypt with stress test	High load	AES remains stable
50	Encrypt with performance logging	Log time and usage	AES performs well

AES Feature : Strong Security

Strong Security - Testcases

#	Test Case	Description	Expected Result
1	Brute-force AES-128	Attempt all key combinations	Computationally infeasible
2	Brute-force AES-192	Attempt all key combinations	Computationally infeasible
3	Brute-force AES-256	Attempt all key combinations	Computationally infeasible
4	Differential cryptanalysis	Analyze input-output differences	No useful patterns found
5	Linear cryptanalysis	Approximate linear expressions	No significant bias
6	Meet-in-the-middle attack	Try combining partial keys	Not effective
7	Related-key attack	Use similar keys	AES resists attack
8	Side-channel attack	Monitor power/timing	Requires physical access
9	Timing attack	Measure encryption time	No key leakage
10	Power analysis attack	Monitor power usage	No key leakage
11	Fault injection attack	Inject hardware faults	AES resists or detects
12	Chosen plaintext attack	Encrypt known plaintexts	No key leakage
13	Chosen ciphertext attack	Decrypt known ciphertexts	No key leakage
14	Known plaintext attack	Use known plaintext-ciphertext pairs	Key not revealed
15	Ciphertext-only attack	Analyze ciphertexts only	Key not revealed
16	Replay attack	Reuse old ciphertext	No effect without context
17	Key recovery attack	Attempt to derive key	Infeasible
18	Key schedule analysis	Analyze key expansion	No weakness found
19	Avalanche effect	Small input change large output change	Confirmed
20	S-box analysis	Analyze substitution layer	Non-linear and secure
21	MixColumns analysis	Analyze diffusion	Strong diffusion confirmed
22	ShiftRows analysis	Analyze permutation	Ensures diffusion
23	Round function analysis	Analyze round transformations	Secure structure
24	Round key independence	Ensure keys differ per round	Confirmed
25	Key sensitivity test	Small key change different ciphertext	Confirmed
26	Plaintext sensitivity test	Small plaintext change different ciphertext	Confirmed
27	Ciphertext indistinguishability	Ciphertext appears random	Confirmed
28	Entropy test	Measure ciphertext randomness	High entropy
29	Statistical test	Analyze ciphertext distribution	Uniform distribution
30	Frequency analysis	Check for patterns	No patterns found
31	Pattern resistance	Encrypt repeating patterns	No visible repetition
32	ECB mode weakness	Identical blocks same ciphertext	Confirmed (insecure mode)
33	CBC mode security	IV prevents repetition	Confirmed
34	GCM mode authentication	Detect tampering	Tag verification fails
35	CTR mode security	Counter ensures uniqueness	Confirmed
36	Key reuse detection	Reuse key with different IV	Still secure (with IV)
37	IV reuse detection	Reuse IV in CBC mode	Security compromised
38	Key derivation security	Use PBKDF2	Secure key generation
39	Password-based key	Use strong password	Secure if high entropy
40	Weak key detection	Use all-zero key	Works but insecure
41	Strong key enforcement	Use random key	Secure encryption
42	Key rotation policy	Rotate keys periodically	Maintains security
43	Key expiration policy	Expire old keys	Prevents long-term exposure
44	Key revocation test	Revoke compromised key	Key no longer usable
45	Secure key storage	Use HSM or TPM	Keys protected
46	Secure key transmission	Use TLS or encrypted channel	Keys not exposed
47	Secure implementation	Use validated library	No known vulnerabilities
48	Compliance check	FIPS 197 compliance	AES certified
49	Cryptanalysis resistance	Review academic attacks	AES remains secure
50	Long-term security	Evaluate against quantum threats	AES-256 recommended

AES Feature : Widely Adopted

Widely Adopted - Testcases

1	Use AES in HTTPS	Secure web traffic	Encrypted communication
2	Use AES in VPN	Encrypt VPN tunnel	Secure connection
3	Use AES in TLS	Transport Layer Security	Data confidentiality
4	Use AES in SSH	Secure shell sessions	Encrypted terminal
5	Use AES in IPsec	Secure IP packets	Encrypted network traffic
6	Use AES in Wi-Fi	WPA2/WPA3 encryption	Secure wireless access
7	Use AES in disk encryption	Full disk encryption (e.g., BitLocker)	Data protected
8	Use AES in file encryption	Encrypt files (e.g., 7-Zip, VeraCrypt)	Files secured
9	Use AES in cloud storage	Encrypt data at rest (e.g., AWS S3)	Data confidentiality
10	Use AES in mobile apps	Secure messaging (e.g., WhatsApp)	End-to-end encryption
11	Use AES in banking apps	Secure transactions	Data protected
12	Use AES in payment systems	Encrypt card data	PCI DSS compliance
13	Use AES in ATMs	Secure PIN and transaction data	Encrypted communication
14	Use AES in smart cards	Secure embedded data	Data encrypted
15	Use AES in passports	e-Passport chip encryption	Identity protection
16	Use AES in government systems	Classified data protection	AES-256 used
17	Use AES in military systems	Secure communications	AES-256 preferred
18	Use AES in healthcare	Encrypt patient records (HIPAA)	Data confidentiality
19	Use AES in legal tech	Secure document storage	Confidentiality ensured
20	Use AES in education	Secure student data	FERPA compliance
21	Use AES in IoT devices	Secure sensor data	Lightweight AES used
22	Use AES in automotive	Secure vehicle communication	Data encrypted
23	Use AES in blockchain	Encrypt wallet keys	Secure storage
24	Use AES in cryptocurrency	Secure private keys	AES-based encryption
25	Use AES in password managers	Encrypt vaults (e.g., LastPass)	Passwords protected
26	Use AES in email encryption	Secure email content	Encrypted messages
27	Use AES in backup systems	Encrypt backups	Data protected
28	Use AES in DRM	Protect digital content	Unauthorized access blocked
29	Use AES in video conferencing	Secure calls (e.g., Zoom)	Encrypted streams
30	Use AES in messaging apps	Secure chats (e.g., Signal)	End-to-end encryption
31	Use AES in browsers	Secure cookies and storage	Data encrypted
32	Use AES in OS security	Encrypt user data (e.g., macOS FileVault)	Data protected
33	Use AES in enterprise software	Secure business data	Compliance ensured
34	Use AES in DevOps	Secure secrets in CI/CD	Encrypted credentials
35	Use AES in container security	Encrypt volumes	Data confidentiality
36	Use AES in database encryption	Encrypt tables/columns	Data protected
37	Use AES in email servers	Secure SMTP/IMAP	Encrypted communication
38	Use AES in digital forensics	Secure evidence storage	Data integrity maintained
39	Use AES in law enforcement	Encrypt case files	Confidentiality ensured
40	Use AES in telecom	Secure voice/data	Encrypted channels
41	Use AES in satellite communication	Encrypt telemetry	Secure transmission
42	Use AES in smart homes	Secure device communication	Data encrypted
43	Use AES in wearables	Encrypt health data	Privacy protected
44	Use AES in gaming	Secure in-game transactions	Data protected
45	Use AES in e-commerce	Secure checkout	PCI DSS compliance
46	Use AES in logistics	Encrypt tracking data	Secure supply chain
47	Use AES in manufacturing	Secure industrial control systems	Data confidentiality
48	Use AES in energy sector	Secure smart grid data	Encrypted communication
49	Use AES in AI/ML pipelines	Encrypt training data	Privacy preserved
50	Use AES in national ID systems	Secure citizen data	Identity protection

AES Feature : Flexible Modes of Operation

Flexible Modes of Operation - Testcases

#	Test Case	Description	Expected Result
1	Encrypt with ECB mode	Basic block-by-block encryption	Identical blocks same ciphertext
2	Encrypt with CBC mode	Chained block encryption	Ciphertext depends on previous block
3	Encrypt with CFB mode	Stream-like encryption	Ciphertext generated
4	Encrypt with OFB mode	Output feedback mode	Stream cipher behavior
5	Encrypt with CTR mode	Counter mode	Parallelizable encryption
6	Encrypt with GCM mode	Authenticated encryption	Ciphertext + authentication tag
7	Decrypt with ECB mode	Decrypt ECB ciphertext	Plaintext recovered
8	Decrypt with CBC mode	Decrypt CBC ciphertext	Plaintext recovered
9	Decrypt with CFB mode	Decrypt CFB ciphertext	Plaintext recovered
10	Decrypt with OFB mode	Decrypt OFB ciphertext	Plaintext recovered
11	Decrypt with CTR mode	Decrypt CTR ciphertext	Plaintext recovered
12	Decrypt with GCM mode	Verify tag and decrypt	Plaintext recovered if tag valid
13	ECB mode pattern test	Encrypt repeating blocks	Identical ciphertext blocks
14	CBC mode IV test	Use different IVs	Different ciphertexts
15	CBC mode IV reuse	Reuse IV	Insecure encryption
16	CFB mode bit-level test	Encrypt bit-by-bit	Works like stream cipher
17	OFB mode bit-level test	Encrypt bit-by-bit	Works like stream cipher
18	CTR mode counter test	Use incrementing counter	Unique ciphertext blocks
19	GCM mode tag verification	Modify tag	Decryption fails
20	GCM mode tag omission	Omit tag	Decryption fails
21	ECB mode weakness	Analyze ciphertext	Patterns visible
22	CBC mode chaining	Analyze block dependency	Strong diffusion
23	CFB mode feedback	Analyze feedback loop	Stream-like behavior
24	OFB mode feedback	Analyze output feedback	Stream-like behavior
25	CTR mode parallelism	Encrypt blocks in parallel	High performance
26	GCM mode integrity	Tamper with ciphertext	Tag mismatch
27	ECB mode with padding	Use PKCS#7	Ciphertext generated
28	CBC mode with padding	Use PKCS#7	Ciphertext generated
29	CTR mode without padding	No padding needed	Ciphertext generated
30	GCM mode with AAD	Add associated data	Authenticated encryption
31	GCM mode without AAD	No associated data	Still secure
32	ECB mode with binary data	Encrypt image	Patterns visible
33	CBC mode with binary data	Encrypt image	Patterns hidden
34	CTR mode with binary data	Encrypt image	Patterns hidden
35	GCM mode with binary data	Encrypt image	Authenticated encryption
36	ECB mode with text	Encrypt text	Patterns visible
37	CBC mode with text	Encrypt text	Patterns hidden
38	CTR mode with text	Encrypt text	Patterns hidden
39	GCM mode with text	Encrypt text	Authenticated encryption
40	ECB mode decryption error	Use wrong key	Garbage output
41	CBC mode decryption error	Use wrong IV	Garbage output
42	CTR mode decryption error	Use wrong counter	Garbage output
43	GCM mode decryption error	Use wrong tag	Decryption fails
44	ECB mode performance	Measure speed	Fastest but insecure
45	CBC mode performance	Measure speed	Moderate speed
46	CTR mode performance	Measure speed	High speed
47	GCM mode performance	Measure speed	High speed + integrity
48	ECB mode compliance	Check FIPS compliance	Not recommended
49	CBC mode compliance	Check FIPS compliance	Approved with padding
50	GCM mode compliance	Check FIPS compliance	Approved and preferred

Reference links

• Reference links