Crypto Performance

I2C Fast Mode (400KHz)

• Without power limitation
• @ 25°C
• VCC = 3.3V
• RSA Signature scheme: RSA SSA PKCS#1 v1.5 without hashing
• ECDSA Signature scheme: ECDSA FIPS 186-3 without hashing
• Encryption/Decryption scheme: RSAES PKCS#1 v1.5
• Hash scheme: SHA256
• Key Derivation scheme: TLS v1.2 PRF SHA256
• RSA Key size: 2048 bits
• ECC Key size: 256 bits (NIST P-256)

Scheme	Algorithm	Performance in ms1	Performance with Shielded Connection in ms1	Notes
Calcualte Signature	RSA	~310	~315	Doesn't include message hashing before calling a toolbox funciton
	ECDSA	~60	~65
Verify signature	RSA	~45	~55
	ECDSA	~85	~90
Diffie-Hellman key agreement	ECC	~60	~65	Based on ephemeral key pair
Key pair generation	RSA	~29002	~2910	Generate 2048 bit RSA key pair
	ECC	~75	~80	Generate 256 bit ECC key pair
Encryption	RSA	~30	~45	Encrypt 127 bytes
Decryption	RSA	~310	~320	Decrypt 127 bytes
Key derivation	PRF as per TLS v1.2	~135	~150
Hash calculation	SHA256	~5 Kbyte/s	~4.5 Kbyte/s	In blocks of 500 bytes

¹ Minimum Execution of the entire sequence in milli seconds, except the External World timings

² RSA key pair generation performance is not predictable and typically have a variation in performance. This could be significantly higher or lower as the one specified in the table which is an average value over collected samples