Software RSA

​​The Software RSA library provides standardized key computation, encryption, decryption, signature and verification functionalities
for all key sizes up to 8192 bits.

Key Features

​PKCS#1 compliant
All key sizes up to 8192 bits
Hardened against SCA
Silicon proven


  • ​​key generation, encryption, decryption, signature and verification functions
  • fully compliant with the PKCS#1 standards
  • all key sizes supported up to 8192 bits
  • core functions ASM-optimized for the targeted processor
  • configurable architecture:
    • adjustable trade-off between performance and RAM footprint
    • dedicated coprocessor available separately (about 10 times faster)
  • state-of-the-art countermeasures against SPA, DPA and DFA attacks
  • typical code size on Cortex-M3 smaller than 15 kbytes
  • ​less than 100 Mcycles to compute a secure 2048-bit RSA signature


  • ​C and Assembly source codes
  • C test vectors
  • compilation scripts (makefile)
  • documents for certifications (FIPS, CC, EMV…):
    • implementation details
    • list of countermeasures with external references
  • design specification

Please contact for any further information.