Is Imp HW enough to support SSL/TLS

I check that SSL/TLS is used to protect the communication b/w Imp HW and agent.
But it seems that Imp HW has small capacity of RAM(60KB) and storage(flash 1.25MB).
Is it sufficient to implement SSL/TLS in imp HW?
SSL/TLS requires quite a large capacity for handshaking (a certificate-based public key negotiation) in addition to encryption.

I can confirm that yes, the imp’s SSL/TLS handshake, which is visible using network-analysis tools such as Wireshark, is not a figment of your imagination.

The code for TLS only takes up a few tens of Kbytes of flash, and while the imp has 128K of RAM not 60, at peak only about 16K of that is taken up by TLS data. The certificate parsing and validation is, as you suggest, the worst part of the protocol for memory consumption.