RSA vs ECDSA - What are the key differences?

In Symmetric encryption the same secret key is used to decrypt an encrypt the message. Examples include RC4, AES, DES, 3DES, etc.

In Asymmetric encryption system two different cryptographic keys (asymmetric keys), called the public and the private keys, are used for encryption and decryption. Examples include RSA, Diffie-Hellman, ECC, etc.

RSA and ECDSA both are asymmetric encryption algo. 

RSA was invented by Ron Rivest, Adi Shamir, and Leonard Adleman in 1977, RSA has been the gold standard when it comes to asymmetric encryption algorithms. RSA uses the prime factorization method for one-way encryption of a message. In this method, two titanic-sized random prime numbers are taken, and they’re multiplied to create another gigantic number.

ECDSA (elliptic curve digital signature algorithm), or ECC (elliptic curve cryptography) as it’s sometimes known, is the successor of the digital signature algorithm (DSA). ECDSA was born when two mathematicians named Neal Koblitz and Victor S. Miller proposed the use of elliptical curves in cryptography. However, it took almost two decades for the ECDSA algorithm to become standardized.

Comparison in Key Length: