Detection of Asymmetric Cryptography

ID: DET0667
Domains: Mobile
Analytics: AN1762, AN1763
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1762

An application generates, imports, or accesses asymmetric keypairs (e.g., RSA/ECC), uses a public key to encrypt outbound data or establish encrypted sessions, and transmits resulting ciphertext in structured communication patterns. Detection correlates keypair lifecycle activity + asymmetric crypto API usage + data transformation + background execution context + network transmission, especially when inconsistent with expected application functionality.

Log Sources
Data Component Name Channel
OS API Execution (DC0021) MobileEDR:telemetry App invokes asymmetric cryptographic operations (e.g., RSA/ECC keypair generation OR public key encryption OR signature operations) on outbound data buffers
MobileEDR:telemetry Keypair generation, import, or access events (public/private key usage) occurring prior to network communication
File Creation (DC0039) MobileEDR:telemetry App writes asymmetric-encrypted blobs or encoded ciphertext to local buffers or files prior to transmission
Application State (DC0123) MobileEDR:telemetry Asymmetric crypto operations occur while app_state=background OR device_locked=true OR no recent user interaction
Application Permission (DC0114) android:MDMLog App not in approved cryptographic or secure communication category performing keypair + encryption + transmission behavior
Mutable Elements
Field Description
TimeWindow Correlation window between keypair usage and outbound communication
AllowedCryptoApps Apps expected to use asymmetric cryptography (e.g., secure messaging, VPN, enterprise auth apps)
ForegroundStateRequired Whether key generation/encryption should occur only during user interaction
KeyGenerationThreshold Frequency of keypair generation/import events considered anomalous
PayloadSizeVariance Expected variability in payload sizes due to asymmetric encryption overhead

AN1763

Indirect evidence of asymmetric cryptographic channel usage inferred through key exchange-like network patterns and application background execution behavior, where direct observation of keypair operations is limited. Detection correlates app entitlement posture + background execution + asymmetric handshake patterns + subsequent encrypted communication.

Mutable Elements
Field Description
TimeWindow Correlation window between initial communication burst and steady encrypted traffic
AllowedAppList Apps expected to perform asymmetric key exchanges
HandshakePatternThreshold Threshold for identifying asymmetric handshake-like traffic patterns
ForegroundStateRequired Whether communication establishment should occur during user interaction