RSA cryptography implementation

[gaminn]

Hi, is there RSA-512 cryptography (or maybe another asymmetric cryptography system) implementation for nrf51 or some implementation that can be easily ported to nrf51?

[Vidar Berg]

Not sure if someone implemented RSA on the 51, but maybe you can use ECC instead? The experimental bootloader in SDK 10.0.0 includes a ECC module used for signing of FW images.

[RK]

ARM bought PolarSSL and rebranded it as mbedTLS, that has an RSA implementation in it. Don't know what the keysize limit is, but the whole thing is free(*) and since ARM bought it, you'd think a port wouldn't be very hard.

(*) it's free but is released under two different licenses so you can determine which if either is unencumbered enough for your use.

[SRA]

Yea, I have been under the impression there is almost no reason you'd use RSA on a micro compared to ECC which stores a secure key in a smaller space and generates faster, uses less power, etc. It's not "more secure" but more efficient.

But then again... If you want to talk to an RSA device I guess you have no choice to use ECC.