Long-Term Android APK Security Engineer

Cliente Freelancer · Remoto · Remoto · freelance · mid · 12.500–37.500 INR

Publicada el 2026-07-24

Descripción de la oferta

Expert Android APK Protection & Security Engineer Long-Term Monthly Contract | Android Security | APK Processing | Python Job Description We are looking for a highly skilled and experienced Android Security and APK Processing Engineer for a long-term monthly contract. The ideal candidate should have strong practical experience with Android application internals, APK file structures, cryptography, binary formats, automation, native libraries, and secure software engineering. The work involves developing and maintaining authorized tools and workflows for Android application protection, secure APK processing, encryption, software integrity, and security research. The successful candidate should be comfortable working at both a high level with Android applications and a low level with DEX bytecode, binary XML, native libraries, ELF structures, cryptographic systems, and automation pipelines. All work must be performed only on software and application files that are owned by the client or for which the client has appropriate authorization to analyze, process, modify, or protect. This is intended to be a long-term working relationship with ongoing technical development and maintenance work. What You Will Work On * Design and implement custom encryption and decryption pipelines for authorized Android APK files * Develop secure APK packaging and application protection workflows * Analyze and process Android APK internals, including DEX bytecode, binary Android XML (AXML), AndroidManifest.xml, ZIP/APK structures, and native .so libraries * Build secure outer application wrappers for protected application components and authorized application packaging workflows * Develop systems that securely process and manage protected application payloads * Parse and programmatically modify AndroidManifest.xml in binary AXML format * Work with cryptographic systems including AES-CBC, AES-GCM, RSA, symmetric encryption, asymmetric encryption, and custom cryptographic workflows * Understand and manipulate DEX file structures, string tables, metadata, and bytecode representations * Analyze and modify native ARM and ARM64 ELF libraries for authorized application protection and compatibility requirements * Implement JNI and native library changes where required * Develop Python scripts for automating APK processing and security workflows * Build reliable, repeatable APK processing pipelines * Work with Android build and packaging tools including AAPT, apktool, zipalign, and apksigner * Maintain and improve existing codebases * Debug complex APK processing, encryption, packaging, and signing issues * Collaborate through Git and follow existing project architecture and coding standards * Research application integrity, anti-tampering, and software protection techniques in authorized environments Required Skills Android APK internals: DEX, AXML, ZIP structure — Expert Cryptography and custom encryption design — Expert AES, RSA, symmetric and asymmetric cryptography — Expert Binary XML (AXML) parsing and processing — Expert Python 3 — Expert Java / Kotlin — Strong C / C++ — Intermediate+ JNI / native Android development — Intermediate+ ELF binary analysis — Intermediate+ ARM / ARM64 native library analysis — Intermediate+ Smali / Dalvik bytecode — Intermediate+ Linux command line and shell scripting — Strong Git version control — Required Bonus Skills The following skills are beneficial but not mandatory: * Experience with Android application security testing * Experience with APK signing and signature schemes including v1, v2, and v3 * Knowledge of ProGuard and R8 obfuscation * Experience with JADX * Experience with apktool * Experience with Frida in authorized security testing environments * Experience with Ghidra * Understanding of Android application installation and package management processes * Experience developing application protection systems * Experience developing integrity verification and anti-tampering systems * Experience with secure application packaging * Experience with Android security research * Experience with vulnerability assessment in authorized environments * Experience with software protection and reverse engineering for applications where appropriate authorization exists Programming Languages and Technologies Python 3 Primary language for: * APK processing pipelines * Automation * Encryption workflows * File processing * Security tools * Backend utilities Java / Kotlin For: * Android application development * Application wrappers * Android runtime components * Application protection mechanisms C / C++ For: * JNI development * Native Android components * Native library work * Performance-critical components Smali / Dalvik Bytecode For: * Authorized bytecode analysis * Application compatibility work * Application protection research Shell / Bash For: * Linux automation * Build pipelines * Deployment scripts * System utilities XML / AXML For: * AndroidManifest.xml processing * Binary XML parsing * Android application metadata handling Tools and Technologies Experience with some or all of the following is preferred: * Python 3 * Java * Kotlin * C * C++ * JNI * Smali * DEX * AXML * AndroidManifest.xml * AES * AES-CBC * AES-GCM * RSA * Cryptography * APK * AAPT * apktool * zipalign * apksigner * JADX * Frida * Ghidra * ELF * ARM * ARM64 * Linux * Bash * Git Work Details Contract Type: Long-term monthly contract Work Type: Remote / Online Hours: Part-time to full-time Work Style: Ongoing development and task-based work Payment: Monthly contract Budget: $380–$420 USD per month Start Date: Immediate / As soon as possible Communication: Freelancer.com messaging and other mutually agreed project communication tools All payments and contracts will follow applicable Freelancer.com platform rules and the agreed project terms. How to Apply Please include the following information in your proposal: 1. Brief Introduction Tell us about your experience with: * Android security * APK processing * Application protection * Cryptography * Binary analysis 2. Previous Work Provide examples of relevant previous projects, if available. Examples may include: * APK processing tools * Application protection systems * Encryption pipelines * Android security tools * Binary analysis projects * Native library work * DEX or AXML processing * Python automation systems Public GitHub repositories, portfolio links, or technical examples are welcome where available. 3. Technical Experience Please clearly describe your experience with any of the following: * AXML parsing and processing * DEX manipulation or analysis * Smali / Dalvik bytecode * Custom encryption pipelines * AES and RSA * APK signing * Native ARM/ARM64 libraries * ELF binary analysis * JNI * Android application protection * Python automation 4. Availability Please tell us: * How many hours per week you are available * Your usual working hours or timezone * Your earliest possible start date 5. Compensation Please confirm whether your expected compensation is within the listed budget of: $380–$420 USD per month If your expectations are different, please mention them clearly in your proposal. Proposal Requirement Generic proposals may not be considered. To confirm that you have carefully read this job description, please include the word: AXML somewhere in your proposal. Authorized Use Requirement All technical work must be limited to software, applications, files, and systems that the client owns or is authorized to analyze, process, modify, test, or protect. The work must comply with applicable laws, software licenses, intellectual property rights, platform rules, and project agreements. The role does not involve unauthorized access to systems, unauthorized modification of third-party software, credential theft, or bypassing access controls without proper authorization. Category Mobile Apps → Android Suggested Skills Android, Android Security, APK, Python, Java, Kotlin, C, C++, Cryptography, Encryption, Binary Analysis, DEX, AXML, Smali, JNI, ELF, ARM, ARM64, Linux, Bash, Git, Reverse Engineering

Skills

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