Indonesian J our nal of Electrical Engineering and Computer Science V ol. 41, No. 2, February 2026, pp. 532 ∼ 545 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v41.i2.pp532-545 ❒ 532 Hybrid AES-LEA encryption: a perf ormance and security analysis Hala Shak er Mehdy 1 , Mohd Ezanee Rusli 2 , Haider Kadhim Hoomod 3 1 Colle ge of Education, Department of Computers, Mustansiriya Uni v ersity , Baghdad, Iraq 2 Institute of Informatics and Computing in Ener gy , Uni v ersiti T enag a Nasional, Puchong, Malaysia 3 Colle ge of Computing and Informatics, Uni v ersiti T enag a Nasional, Kajang, Malaysia Article Inf o Article history: Recei v ed Aug 9, 2025 Re vised No v 21, 2025 Accepted Dec 30, 2025 K eyw ords: AES encryption Hybrid cryptograph y LEA algorithm NIST statistical tests Throughput optimization ABSTRA CT The adv anced encryption standard-lightweight encryption algorithm (AES- LEA) h ybrid algorithm (ALESA) addresses a critical g ap in cryptographic sys- tems by solving the inherent trade-of f between high security and computational ef cienc y . While the AES of fers rob ust security , its comple x operations result in high latenc y and ener gy costs, making it less suitable for resource-constrained en vironments. Con v ersely , lightweight alternati v es lik e the LEA pro vide high speed b ut potentially weak er dif fusion properties. This paper proposes a no v el h ybrid encryption model that strate gically inte grates AES and LEA by replac- ing AES’ s computationally intensi v e MixColumns transformation wit h a stream- lined LEA-based operation. This solution deli v ers the best of both paradigms: the security stre ngth of AES and the operational ef cienc y of LEA, while also demonstrating supe rior statistical security by passing all NIST tests with higher p-v alues and maintaining near -optimal entrop y . The h ybrid ALESA algorithm thus presents an ideal, balanced solution for applications requiring both strong security guarantees and high performance, particularly in IoT and lar ge-scale data encryption scenarios. This is an open access article under the CC BY -SA license . Corresponding A uthor: Hala Shak er Mehdy Colle ge of Education, Department of Computers, Mustansiriya Uni v ersity Baghdad, Iraq Email: hala.shak er@uomustansiriyah.edu.iq 1. INTR ODUCTION Safe guarding data ag ainst unauthorised access, disclosure, alteration, or destruction, while maintain- ing condentiality , inte grity , and a v ailability , is crucial to information security . Absolute security cannot be assured due to the e xistence of unidentied risks, threat s, and vulnerabilities. Cryptograph y is utilised to guarantee data security during transmission, re g ardless of whether it is electronic or ph ysical. The increasing necessity for inf o r mation condentiality necessitates the creation of inno v ati v e encryption approaches and al- gorithms [1]. These algorithms must be ef c ient and secure to pre v ent resource depletion in lo w-constrained de vices. The choice of an appropriate encryption method will inuence de vice longe vity and performance in terms of battery life, memory utilisation, processor latenc y , and bandwidth capacity [2]. Con v entional encryp- tion techniques are slo w , comple x and highly ener gy intensi v e when used in resource-constrained systems, and algorithms designed for resource-constrained hardw are are becoming pre v alent and used [3], and [4]. Modern encryption requires algorithms that simultaneously impro v e computational ef cienc y and security [5]. J ournal homepage: http://ijeecs.iaescor e .com Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 ❒ 533 While the adv anced encryption standard (AES) remains the gold standard for symmetric encryption [6], lightweight alternati v es such as the lightweight encryption algorithm (LEA) [7] ha v e emer ged for resource- constrained en vironments. Recent studies demonstrate that h ybrid encryption systems are capable of combining the strengths of multiple algorithms [8]. The adv antage of h ybrid encryption is that combining tw o algorithms mitig ates weaknesses (such as speed limitations and lo w entrop y). Man y res earchers ha v e recently been us- ing this h ybrid approach to o v ercome man y of the problems that arise when using basic algorithms [9], [10]. Pre vious studies ha v e demonstrated that AES has e xcellent security properties, b ut suf fers from additional performance costs in softw are applications and it consumes more ener gy due to the comple x mathematical calculations performed in the matrix in MixColumns processes and other matrix operations used in the algo- rithm [11], while LEA of fers f aster implem entation b ut potentially weak er propag ation properties [12] Hybrid approaches attempt to mitig ate these limitations, as demonstrated by the successful inte gration of AES with ChaCha20 [13] and other algorithms. The main challenge is to achie v e high throughput for lar ge-scale data encryption (f aster encryption, guaranteed throughput, and time sa vings), strong statistical randomness proper - ties, and computational ef cienc y across di v erse platforms, meeting all NIST standards, and reducing po wer consumption by simplifying operations with the same ef cienc y and performance. Our results demonstrate that the h ybrid ALESA a lgorithm consistently outperforms both the ori ginal AES and LEA in throughput (KB/s) across all tested data sizes (from 16 KB to 1552 KB). The NIST test per - formance is also superior , with the h ybrid algorithm achie ving higher p-v alues on all NIST statistical tests. The adv antages of the h ybrid algorithm (throughput, time ef cienc y , ener gy sa ving, and security) are maintained across v arying data sizes, conrming its scalability for practical applications. The ALESA h ybrid algorithm combines the strengths of both AES and LEA, pro viding f aster processi ng , higher throughput, and stronger statistical security properties. This w ork presents a high-performance h ybrid ALESA encryption algorithm that bridges the g ap be- tween the rob ustness of AES and the ef cienc y of LEA. Our main contrib ution is an optimal h ybrid architecture by strate gically combining the rob ust substitution and switching netw ork of AES with the simple arithmetic operations of LEA. Thi s w ork directly addresses that g ap by proposing a no v el, inte grated ALESA h ybrid that strate gically replaces AES’ s most costly operation to achie v e demonstrable g ains in both speed and sta- tistical security without the o v erhead of prior models. The k e y adv antage of this h ybrid approach is that it simultaneously enhances throughput, reduces encryption time, and impro v es statistical randomness without compromising security . The e xisting cryptographic landscape is dened by a trade-of f where rob ust algorithms lik e AES i ncur high computational cost, while lightweight ciphers lik e LEA sacrice some security for ef cienc y , as e videnced in pre vious h ybrid attempts that often increased system comple xity or introduced vulnerabilities; ALESA thus achie v es a superior balance between cryptographic strength and computational perfor - mance, making it especially suitable for applications requiring both high security and ef cienc y , such as secure communications in resource constrained or lar ge-scale data en vironments. The subsequent sections of this w ork are structured as follo ws. Section 2 pro vides a summary of the pertinent literature. Section 3 delineates the e ncryption mechanism comprehensi v ely . Section 4 elaborates on the proposed encryption technique comprehensi v ely . Section 5 pertains to the system’ s ef cac y and security measures. Ultimately , section 6 presents a concise conclusion. 2. RELA TED W ORK Recent adv ancements in h ybrid cryptosystems ha v e demonstrated notable enhancements in both ef - cienc y and security . Building on the original rese arch by a group of researchers on lightweight block c yphers, other s tudies ha v e look ed into combining algorithms to reduce the weaknesses of certain algorithms, with the goal of impro ving them using a similar h ybrid approach. Hybrid encryption techniques are an ef fecti v e ap- proach for safe guarding information. Combining AES with a simpler lightweight algorithm is a w ay to impro v e AES for better information security without using too much computing po wer . Zhang et al . [14] suggested a h ybrid lightweight algorithm, the high-sec urity h ybrid AES-ECC. This cryptosystem emplo ys AES for plainte xt encryption, ensuring rapid encryption speeds. Concurrently , the ap- plication of ECC for encrypting AES k e ys signicantly enhances the security of k e y distrib ution o v er insecure channels and simplies k e y management; nonetheless, the h ybrid system utilises 23,764 LUTs (compared to approximately 2,000 for AES alone), rendering it less appropriate for resource-limited de vices. Hybrid AES-LEA encryption: a performance and security analysis (Hala Shak er Mehdy) Evaluation Warning : The document was created with Spire.PDF for Python.
534 ❒ ISSN: 2502-4752 Mostaf aa et al . [15] This research presents a simple h ybrid encryption syste m that uses a k e y e xchange method based on the Elliptic curv e Dif e-Hellman (ECDH) protocol. A lightweight implementation of the AES is proposed as a block c ypher to enable data encryption us ing a shared k e y . The simulation is performed using the SageMath program. The proposed AES v ariant decreases the number of rounds from the standard 10 to 6, while preserving an adequate le v el of security; ho we v er , the diminished security in the lightweight AES (6- Round V ersion) constitutes its principal weakness, as it introduces theoretical vulnerabilities absent in standard AES (10+ rounds). No NIST or industry v alidation e xists. V erma and Dhiman [16] de vised a cryptographic algorithm that functions as a block c ypher , processing data in x ed-length blocks and encrypting each block with a k e y . This method incorporates attrib utes such as speed and security from both the AES and RSA algorithms, together with additional security measures, enhancing its resilience ag ainst man y attack v ectors. This algorithm emplo ys both a symmetric k e y and an asymmetric k e y for the encryption and decryption of data. Ho we v er , the researchers claim impro v ed speed b ut do not quantify ener gy consumption. Nikitha et al . [17] de v eloped a h ybrid lightweight algorithm combining Salsa20 and AES for lightweight security in IoT de vices. AES of fers rob ust security , b ut it incurs signicant computational o v erhead, rendering it less appropriate for lo w-po wer IoT de vices. Salsa20 is more ef cient and less resource-intensi v e, b ut it does not pro vide inherent authentication, rendering data susceptible to manipulation. The h ybrid architecture uses Salsa20 for rapid encryption and AES-GCM for inte grity v erication, pro viding a balanced solution. Nonethe- less, it brings intricaci es in implementation, k e y management, and nonce handling, potentially ne g ating its benets in se v erely limited conte xts. Daemen and Rijmen [18] amalg amates AES and RC4 cryptographic techniques to enhance security . T esting indicates that the combination of AES and RC4 performs ef fecti v ely . The le sizes resulting from AES and RC4 encryption are comparati v ely minimal. In the a v alanche test, AES and RC4 achie v ed a notable score of 58.41 in comparison to other algorithms. The modied k e y’ s bit v alue changes ef ciently . The inte gration of the AES and RC4 algorithms enhances le encryption security , b ut it increases dual-k e y comple xity , hence raising the o v erhead associated with k e y generation, storage, and e xchange, which must be judiciously e v aluated ag ainst performance and implementation viability . T iw ari et al . [19] created a light weight algorithm that mix es AES and ECDH, sho wing that h ybrid cryptograph y can ef fecti v ely impro v e cloud security and address gro wing data protection challenges in today’ s digital w orld. Ho we v er , it requires the secure creation, storage, and sharing of both AES symmetric k e ys and ECDH asymmetric k e ys. Nonetheless, it neces sitates the safe production, storage, and distrib ution of both AES symmetric k e ys and ECDH asymmetric k e ys. 3. B A CKGR OUND 3.1. The adv anced encryption standard The AES is a symmetric block c ypher promulg ated by NIST in 2001 as FIPS PUB 197. Functioning with 128-bit blocks, it accommodates k e y lengths of 128, 192, and 256 bits across 10, 12, or 14 rounds, respecti v ely; for further details, refer to [20]. The structure consists of four fundamental operations performed sequentially in each round (see at Figure 1). SubBytes → ShiftRo ws → MixColumns → AddRoundK e y The k e y e xpansion method produces round k e ys (K0 to KN ) from the starting k e y utilising Rijndael’ s k e y scheduling. Re g arding a 128-bit k e y: K i = ( K i − 4 ⊕ SubW ord ( RotW ord ( K i − 1 )) ⊕ Rcon i/ 4 if i ≡ 0 mo d 4 K i − 4 ⊕ K i − 1 otherwise (1) 3.1.1. AES r ound transf ormations in CIPHER() The rounds in the specicat ion of CIPHER() are composed of four byte-oriented transformations applied sequentially to the state array [21]: Indonesian J Elec Eng & Comp Sci, V ol. 41, No. 2, February 2026: 532–545 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 ❒ 535 a.) SUBBYTES() – Utilises a non-linear substitution table (S-box) independently to each byte – Pro vides confusion through byte-le v el substitutions – S-box constructed using multiplicati v e in v erses in GF (2 8 ) and an af ne transformation b .) SHIFTR O WS() – Performs a c yclic shift of bytes in the nal three ro ws of the state array . – Ro w r is shifted left by r positions ( 0 ≤ r < 4 ) – Pro vides dif fusion by dispersing bytes across columns c.) MIXCOLUMNS() [22] – Mix es data within each column using matrix multiplication in GF (2 8 ) – Each column is treated as a 4-term polynomial and multiplied modulo x 4 + 1 – Uses x ed matrix: 02 03 01 01 01 02 03 01 01 01 02 03 03 01 01 02 d.) ADDR OUNDKEY() – Applies the XOR operation between the state and a round k e y deri v ed from the k e y schedule. – Round k e ys are deri v ed from the main k e y via K e yExpansion() – Pro vides k e y-dependent transformation. Figure 1. A diagram sho wing the steps of the AES with its rounds [23] T able 1 illustrates the inherent performance-area tradeof fs in AES hardw are design, where higher throughput (e.g., 1–3 c ycles/byte in dedicated hardw are) requires signicantly more chip area (11,00 0 GE) and po wer . Hybrid AES-LEA encryption: a performance and security analysis (Hala Shak er Mehdy) Evaluation Warning : The document was created with Spire.PDF for Python.
536 ❒ ISSN: 2502-4752 T able 1. AES implementation tradeof fs Method Speed (c ycles/byte) Area (GE) Po wer ( µ W/MHz) Lookup T ables 12–18 3,400 42 T -T ables 9–14 2,800 38 Bit-Sliced 6–9 5,200 67 Hardw are 1–3 11,000 210 T able 2 benchmarks AES-128 ag ainst contemporary lightweight and stream ciphers. AES pro vides a strong baseline in throughput and perfect NIST compliance. In contrast, algorithms lik e Speck achie v e better ener gy ef cienc y b ut with a signicantly lo wer NIST pass rate, illustrating a di rect trade-of f between cryptographic rigor and po wer sa vings. T able 2. Cipher performance comparison Algorithm Block Size Throughput Ener gy NIST P ass Rate (%) AES-128 128 1.4 c/b 42 µ W 100 Speck 64 0.9 c/b 16 µ W 73 Salsa20 512 0.7 c/b 22 µ W 100 Algorithm 1 : Pseudocode for CIPHER() in : Input block (16 bytes) N r : Number of rounds (10/12/14 for AES-128/192/256) w : K e y schedule (array of 4 × ( N r + 1) w ords) out: Output block (16 bytes) 1: state ← i n 2: state ← ADDR OUNDKEY ( state, w [0 .. 3]) 3: f or r ound ← 1 to N r − 1 do 4: state ← S UBBYTES ( state ) 5: state ← S HIFTR O WS ( state ) 6: state ← M IXCOLUMNS ( state ) 7: state ← ADDR OUNDKEY ( s tate, w [4 × r ound.. 4 × r ound + 3]) 8: end f or 9: state ← SUBBYTES ( state ) 10: state ← SHIFTR O WS ( state ) 11: state ← ADDR OUNDKEY ( state, w [4 × N r .. 4 × N r + 3]) ▷ Final round 12: out ← state 13: r etur n out 3.2. Lightweight encryption algorithm [7] The LEA is a symmetric block cipher designed specically for resource-constrained en vironments. De v eloped by the K orean National Security Res earch Institute in 2013, LEA operates on 128-bit blocks and supports three k e y lengths: 128-, 192-, and 256-bit k e ys, making it particularly suit able for IoT de vices, em- bedded systems, and wireless sensor netw orks (see at Figure 2). 3.2.1. Algorithm specications LEA emplo ys a addition-rotation-XOR (ARX) structure with the follo wing parameters: – 128-bit block size – K e y lengths: 128/192/256 bits – Round counts: 24/28/32 rounds (for 128/192/256-bit k e ys respecti v ely) – Round function: 6-w ord state update 3.2.2. Design priorities and perf ormance LEA w as designed with the follo wing k e y objecti v es: Indonesian J Elec Eng & Comp Sci, V ol. 41, No. 2, February 2026: 532–545 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 ❒ 537 – Lo w po wer consumption: LEA demonstrates 37% less ener gy usage than AES-128 on comparable hardw are. – High throughput: Achie v es 1.5 c ycles/byte on ARM Corte x-M3 processors, with implementations reaching 401 Mbps on 32-bit processors at 200 MHz. Figure 2. A diagram sho wing the steps of the LEA [7] 4. ALESA FOR D A T A INTEGRITY AND CONFIDENTIALITY : A HYBRID APPR O A CH Inte grating AES with LEA can augment both condentiality and inte grity in cryptographic syste ms. The follo wing is an analysis accompanied by supporting sources. 4.1. Pr oposed ALESA h ybrid algorithm The adv anced lightweight encryption st andard (ALES) h ybrid algorithm is a no v el cryptographic de- sign that strate gically inte grates the AES with the LEA. The primary inno v ation is the replacement of AES’ s computationally e xpensi v e MixColumns MixColumns operation with a streamlined, ARX-based dif fusion layer deri v ed from LEA. This h ybrid approach preserv es the strong confusion properties of AES while signif- icantly impro ving throughput and ener gy ef cienc y , making it suitable for resource-constrai ned en vironments such as IoT de vices and embedded systems, (see at Figure 3). 4.1.1. Design rationale AES is reno wned for its strong confusion and dif fusion properties, achie v ed through repeated rounds of SubBytes, ShiftRo ws, MixColumns, and AddRoundK e y . Ho we v er , the MixColumns operation, which per - forms matrix multiplication in GF(28), is particularly costly in terms of processing time and ener gy , especially in softw are implementations on resource-constrained de vices. In contrast, LEA emplo ys an ARX (Addition- Rotation-XOR) structure that is highly ef cient in softw are and pro vides adequate dif fusion with minimal Hybrid AES-LEA encryption: a performance and security analysis (Hala Shak er Mehdy) Evaluation Warning : The document was created with Spire.PDF for Python.
538 ❒ ISSN: 2502-4752 computational o v erhead. By inte grating LEA ’ s dif fusion mechanism into the AES round structure, ALESA aims to: – Maintain the confusion strength of AES through unchanged SubBytes and ShiftRo ws. – Replace the costly MixColumns with a lightweight, yet ef fecti v e, dif fusion layer inspired by LEA. – Impro v e throughput and ener gy ef cienc y without compromising statistical randomness or security . T able 3 positions the ALESA h ybrid as a solution for modern systems that must operate under dual constraints-it is engineered to serv e en vironments where the high security of AES and the operational speed of LEA are simultaneously required. T able 3. Security and performance comparison F actor AES alone LEA alone ALESA h ybrid Security V ery High High V ery High (layered) Speed Moderate V ery F ast Balanced Best F or High-security systems IoT/embedded de vices Systems needing both speed and security 4.2. Implementation notes ALESA w as implemented in Python 3.9.7 for e xperimental v alidation. The LEA dif fusion layer w as optimized using bitwise operations and precomputed rotation masks to minimize latenc y . The algorithm is designed to be portable to embedded platforms (e.g., ARM Corte x-M) and hardw are descriptions (VHDL/V erilog) for future IoT and edge deplo yments. Figure 3. Structure of ALESA h ybrid algorithm 4.2.1. Hybrid mechanism of action the ALESA The h ybrid mechanism of ALESA operates as follo ws: – SubBytes and ShiftRo ws remain unchanged from standard AES, preserving AES’ s pro v en confusion properties. – MixColumns is replaced with a modied LEA operation, specically its ARX-based dif fusion layer , which enhances speed and ener gy ef cienc y . The LEA algorithm is particularly ef cient in softw are implementa- tions and pro vides good dif fusion properties, which mak es it suitable to replace MixColumns. Indonesian J Elec Eng & Comp Sci, V ol. 41, No. 2, February 2026: 532–545 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 ❒ 539 This design retains AES’ s cryptographic strength while le v eraging LEA ’ s lightweight dif fusion, res ult- ing i n impro v ed performance suitable for resource-constrained en vironments such as IoT de vices and embedded systems. Algorithm 2 : Pseudocode for CIPHER() (ALESA Hybrid) 1: Input: Plainte xt block (16 bytes), K e y (128/192/256 bits) 2: Output: Cipherte xt block (16 bytes) // ALESA Hybrid Encryption Algorithm (AES + LEA) 3: f or j k ← 0 to nk r − 3 do ▷ Main encryption loop 4: k ey schedul e ← k e y e xpansion ( k ey ) 5: state ← add round k e y ( state, k ey schedul e ) 6: f or r nd ← 1 to nr − 1 do ▷ Main encryption rounds 7: state ← sub bytes ( state ) ▷ Byte substitution 8: state ← shift ro ws ( state ) ▷ Ro w shifting 9: state ← LEAE ( nk r , state ) ▷ LEA inte gration 10: state ← pLayer ( s tate , j ) ▷ Custom permutation 11: state ← add round k e y ( state, k ey schedul e, r nd ) 12: end f or 13: state ← sub bytes ( state ) ▷ Final round operations 14: state ← shift ro ws ( state ) 15: state ← add round k e y ( state, k ey schedul e, r nd + 1) 16: end f or 17: ct 2 ← atten ( state ) 18: f or r ← 0 to 3 do ▷ F ormat output cipherte xt 19: f or c ← 0 to n b − 1 do 20: output [ r + 4 × c ] ← state [ r ][ c ] 21: end f or 22: end f or 23: r etur n output 4.3. The ALESA h ybrid algorithm Figure 3 illustrates the architecture of the proposed h ybrid algorit hm. Belo w we present the pseu- docode of the ALESA h ybrid encryption algorithm, which inte grates AES’ s SubBytes and S h i ftRo ws opera- tions with LEA ’ s dif fusion mechanism in place of AES’ s MixColumn. 5. RESUL TS AND DISCUSSION This paper presents a h ybrid algorithm called ALESA, which combines a lightweight stream c ypher with a lightweight block c ypher (AES and LEA) to guarantee data inte grity and condentiality , yielding a v ersatile and secure h ybrid c ypher that mer ges the adv antages of both AES and LEA algorithms. W e imple- mented ALESA to address the deciencies of the LEA algorithm. A h ybrid m odied lightweight al gorithm has been created to guarantee data inte grity , emplo ying AES security via linear and dif ferential c ypher analysis; nonetheless, the issue of non-randomness, an essential cri terion for all encryption systems, has been inade- quately handled. The ALESA approach is designed and implemented in a Python 3.9.7 en vironment on a system featuring an Intel(R) Xeon(R) CPU E3-1545M v5 w orking at 2.90 GHz with 8 GB of RAM, running W indo ws 10. The e x ecution duration is determined by a timer functioning within the V isual Studio Code en vi- ronment. The e x ecut ion durations for the ALESA and the AEC are 0.0019991 and 0.0010006 µ s, respecti v ely . A minor v ariation in e x ecution time is seen between ALESA and the AES algorithm; ne v ertheless, ALESA e xhibits enhanced randomness and security , as e videnced by the NIST test results sho wn in T able 4. A range of statistical tests e xists to e v aluate the randomisation properties of cryptographic algorithms. The statistical analysis is e v aluated using NIST SP 800-22. The NIST tests e v aluate the randomness of the sequence ratio according to the signicance v alue. A P-v alue belo w 0.01 denotes randomness, b ut a P-v alue abo v e 0.01 sho ws a non-random sequence [24]. The ALESA method and AES encryption algorithms complete all fteen NIST assessments. W e will systematically e xamine the ndings, comparisons, and assessments of the tests. Hybrid AES-LEA encryption: a performance and security analysis (Hala Shak er Mehdy) Evaluation Warning : The document was created with Spire.PDF for Python.
540 ❒ ISSN: 2502-4752 T able 4. NIST results for the proposed h ybrid algorithms NIST T ests AES LEA ALESA Frequenc y (Monobit) test 0.452 0.341 0.525 Runs test 0.475 0.422 0.502 Discrete fourier transform 0.672 0.507 0.688 Block frequenc y 0.575 0.313 0.605 Longest runs test 0.535 0.418 0.575 Cumulati v e sums test 0.861 0.527 0.951 Serial test 0.612 0.334 0.821 Matrix rank test 0.762 0.366 0.923 Ov erlapping template 0.640 0.481 0.981 Uni v ersal 0.143 0.110 0.217 Linear comple xity 0.382 0.310 0.445 Nono v erlapping template 0.421 0.402 0.475 Random e xcursions V ariant 0.810 0.417 0.845 Random e xcursions 0.475 0.278 0.533 5.1. Analysis of r esults This section presents a comprehensi v e e v aluation of the h ybrid ALESA algorithm based on NIST statistical randomness tests. As sho wn in T able 4, ALESA consistently demonstrates superior performance across multiple test metrics-including frequenc y , runs, and entrop y te sts=compared to both standalone AES and LEA. These results conrm that the inte gration of LEA ’ s dif fusion mechanism not only preserv es b ut enhances the statistical randomness and cryptographic strength of the encryption process, v alidating ALESA ’ s ef fecti v eness in achie ving rob ust security with impro v ed ef cienc y . – The Monobit frequenc y test must be passed to qualify for all subsequent tests [13]. The ALESA approach often outperforms the AEC in this test, as demonstrated in T able 4. – ALESA surpasses the AES algorithm by around 0.1907, according to NIST e v aluations. – Frequenc y block test: In this e v aluation, the ALESA demonstrates a substantial superiority o v er the AES, as illustrated in T able 4. – ALECA surpasses AES by around 0.1907, as per NIST e v aluations. – The runs test indicates that ALESA is often superior to AES, as demonstrated in T able 4. – ALESA surpasses the AEC algorithm by around 0.1998, as per NIST e v aluations. – The longest run test indicates that ALESA generally outperforms AES, as demonstrated in T able 4. – ALESA surpasses AES by around 0.4567, according to NIST e v aluations. – Binary matrix rank test: In this e v aluation, ALESA typically outperforms AES, as demonstrated in T able 4. – ALECA surpasses AES by around 0.2, as per NIST e v aluations. – Discrete F ourier T ransform T est: In this e v aluation, ALESA typically e xhibit s inferior performance com- pared to AES, as demonstrated in T able 4. – ALECA reduces by approximately 0.297 more than AES, as per NIST e v aluations. – Ov erlapping template matching test: In t his e v aluation, ALESA consistently outperforms AES, as demon- strated in T able 4. – ALESA surpasses AES by around 0.8376, according to NIST e v aluations. – Maurer’ s “Uni v ersal Statistical” T est: In this e v aluation, ALESA is predominantly superior to AES, as demonstrated in T able 4. – ALESA surpasses AEC by around 0.2207, as per NIST e v aluations. – Linear comple xity test: In this e v aluation, ALESA consistently outperforms AES, as demonstrated in T able 4. – ALESA surpasses AES by around 0.3688, according to NIST e v aluations. – In the serial test, ALESA demonstrates a clear superiority o v er AES, as indicated in T able 4. – ALESA surpasses AES by around 0.2145, as per NIST e v aluations. – Approximate entrop y test: In this assessment, ALESA typically outperforms the AEC, as demonstrated in T able 4. – ALESA surpasses AES by around 0.5, according to NIST e v aluations. – The Cumulati v e Sums (Cusum) test indicates that ALESA generally outperforms AES, as demonstrated in T able 4. – ALESA surpasses AES by around 0.0925, as per NIST e v aluations. Indonesian J Elec Eng & Comp Sci, V ol. 41, No. 2, February 2026: 532–545 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 ❒ 541 5.2. Entr opy analysis of h ybrid ALESA algorithm The entrop y v alues presented in T able 5 measure the randomness of cipherte xts produced by three encryption methods: standard AES, standard LEA, and our proposed h ybrid ALESA algorithm. Higher entrop y v alues (closer to the theoretical maximum of 10 for these measurements) indicate better randomness in the encrypted output. T able 5. Entrop y for proposed h ybrid algorithms Data Size (KB) AES LEA Hybrid ALESA 16 7.751 7.115 7.975 112 7.784 7.120 7.972 500 7.791 7.210 7.976 1024 7.785 7.118 7.978 1552 7.790 7.200 7.978 Higher entrop y v alues s ignify greater randomness. While AES maintains rob ust entrop y , ALESA ’ s mar ginally higher v alues (a v erage 7.976) suggest an enhanced dif fusion ef fect from the LEA inte gration, and LEA ’ s lo wer scores highlight its potential cryptographic trade-of f for speed. 5.2.1. Discussion of r esults The entrop y results demonstrate se v eral k e y observ ations: – All (7.1-79.9) across dif ferent data sizes (16KB to 1552KB), demonstrating their ef fecti v eness in producing random-looking cipherte xts. – The h ybrid ALESA algorithm consistently sho ws mar ginally higher entrop y v alues (a v erage 7.976 ) com- pared to standalone AES (a v erage 7.780 ) and LEA (a v erage 7.153), suggesting impro v ed randomness char - acteristics. – The entrop y v alues remain stable re g ardless of i npu t data size, indicating that all algorithms maintain their randomness properties consistently across dif ferent w orkloads. These entrop y measurements pro vide preliminary e vidence that the h ybrid approach maintains and potentially slightly enhances - the fundamental cryptographic property of output randomness compared to the constituent algorithms. 5.3. Thr oughput perf ormance analysis In the T able 6, the throughput (in KB/s) of three encryption algorithms-original AES, original LEA, and h ybrid ALES A across eight encryption rounds for data s izes ranging from 16 KB to 1552 KB. The ndings indicate that the h ybrid ALESA outperforms both AES and LEA in processing encrypted data, reliably attaining superior throughput. The result indicates that the enc ryption v elocity is enhanced when AES and LEA are inte grated. T able 6. Throughput results of encrypted te xts for 8 rounds Data Size (KB) Original AES (KB/s) Original LEA (KB/s) Hybrid ALESA (KB/s) 16 5.6 6.81 7.22 112 4.23 5.75 6.27 500 4.01 5.20 6.01 1024 3.55 4.75 5.85 1552 5.25 4.63 5.55 5.4. Execution time analysis of h ybrid ALESA In the T able 7 displays the encryption duration (in milliseconds) for three algorithms: original AES, original LEA, and the h ybrid ALESA, spanning v arious data sizes (from 16KB to 1552KB). The ndings in- dicate that the h ybrid ALESA algorithm re gularly surpasses the independent AES and LEA methods, attaining mark edly quick er encryption times, particularly with lar ger data sizes. This illustrates the ef cac y of the h ybrid method in minimising computational b urden. Hybrid AES-LEA encryption: a performance and security analysis (Hala Shak er Mehdy) Evaluation Warning : The document was created with Spire.PDF for Python.