ECC
Definition
Elliptic Curve Cryptography. Smaller keys for equivalent security; 256-bit ECC is roughly equivalent to 3072-bit RSA. Used in ECDSA signatures, ECDH key exchange and Ed25519.
- Full name
- Elliptic Curve Cryptography
- Key size example
- 256-bit ECC roughly equals 3072-bit RSA
- Common uses
- ECDSA, ECDH, Ed25519
- Advantage
- Smaller keys for equivalent security
Common questions
Why does ECC matter in digital evidence involving encrypted communication?+
Many modern messaging apps and TLS connections use ECC-based key exchange and signatures, so recognising ECDH or Ed25519 in captured traffic or key material tells an examiner what cryptographic protections are in place and what recovery approaches are even feasible.
Is ECC weaker than RSA because its keys are smaller?+
No. The security comes from the mathematical difficulty of the elliptic curve discrete logarithm problem, which is harder per bit than factoring, so a much shorter ECC key can match a far longer RSA key at the same security level.
Related terms
- Asymmetric Cryptography
- Cryptosystem that uses a key pair: a public key (shareable) and a private key (secret). Built on mathematical trapdoor functions where the...
- Digital Signature
- Cryptographic proof of authenticity, integrity and non-repudiation. Sign by encrypting a hash of the message with the signer's private key; verify by...
- DSC
- Digital Signature Certificate. An Indian X.509 certificate issued by a CCA-licensed CA. Class 3 is the current mandatory tier for income tax,...
- Hash Function
- Deterministic function that maps an input of arbitrary length to a fixed-length output. A cryptographic hash adds pre-image resistance, second pre-image resistance,...
- HMAC
- Hash-based Message Authentication Code, RFC 2104. Combines a secret key with a hash function to produce a MAC; immune to the length-extension...
- PKI
- Public Key Infrastructure. The set of roles (CA, RA, VA) and artefacts (X.509 certificates, CRL, OCSP) that bind a public key to...
- RSA
- Rivest-Shamir-Adleman, 1977. Public-key cryptosystem based on the hardness of factoring a product of two large primes. Common sizes today: 2048-bit (standard), 3072-bit...
- Trapdoor Function
- A one-way function with a secret 'trapdoor' that makes the reverse direction tractable. RSA's trapdoor is the factorisation of n into p...