RSA vs ECC

• RSA (Rivest-Shamir-Adleman): RSA is one of the most widely used public-key cryptographic algorithms. It relies on the mathematical difficulty of factoring large prime numbers.
• ECC (Elliptic Curve Cryptography): ECC is a modern public-key cryptographic algorithm that uses the algebraic structure of elliptic curves over finite fields. It provides equivalent security to RSA but with much smaller key sizes.

RSA Key Sizes:

• 1024 bits: Considered obsolete due to vulnerabilities.
• 2048 bits: Minimum recommended for secure communications today.
• 3072 bits or 4096 bits: Used for higher security but results in slower performance.

ECC Key Sizes:

• 160-bit ECC: Comparable to 1024-bit RSA in security.
• 256-bit ECC: Comparable to 3072-bit RSA in security.
• 512-bit ECC: Comparable to RSA-15k security levels, but rarely used as ECC with 256-bit is already highly secure.

ECC provides the same level of security as RSA with much shorter key lengths, making it more efficient.

 

 

RSA:

• Slower in key generation, encryption and decryption, especially with larger key sizes (2048 bits and above).
• Requires significantly more computational power and storage as key sizes increase.

ECC:

• Faster in key generation, encryption and decryption, especially with smaller key sizes.
• More efficient for mobile and embedded systems with limited processing power and memory.

ECC is more computationally efficient and performs better in environments with resource constraints.

 

RSA:

• Widely supported in legacy systems and across various platforms (browsers, email, VPNs).
• Commonly used for digital signatures, encryption, and key exchanges in TLS/SSL.

ECC:

• Increasingly adopted for modern systems, especially for mobile devices, IoT devices, and secure communications requiring high performance and low power usage.
• Used in SSL/TLS protocols (P-256 and P-384 curves), blockchain technologies (Bitcoin, Ethereum), and mobile communications.

RSA remains dominant in older systems, but ECC is favoured in new applications requiring efficiency, especially in mobile and IoT.

 

RSA:

• Vulnerable to quantum computers due to Shor’s algorithm, which can efficiently factor large integers.

ECC:

• Also vulnerable to quantum attacks but may last longer than RSA before quantum computing becomes a practical threat.

Neither RSA nor ECC is quantum-resistant, but ECC’s shorter key sizes make transitioning to post-quantum cryptography easier.

RSA:

• Security depends on the difficulty of factoring large composite numbers.
• As computational power grows, RSA key sizes must increase to maintain security, which results in performance trade-offs.

ECC:

• Security is based on the Elliptic Curve Discrete Logarithm Problem (ECDLP), which is significantly harder to solve than the integer factorisation problem RSA relies on.
• Provides stronger security per bit of key length compared to RSA.

ECC is more resistant to attacks compared to RSA at equivalent key strengths.

RSA:

• Larger key sizes require more bandwidth and storage, making it less efficient for environments with limited resources, such as mobile devices or low-bandwidth networks.

ECC:

• Smaller key sizes reduce bandwidth and storage requirements, making it suitable for modern communication protocols where efficiency is paramount.

ECC’s smaller key sizes make it more suited for environments with storage and bandwidth limitations.

ECC is generally considered more efficient than RSA, offering the same level of security with smaller key sizes, faster performance, and reduced storage and bandwidth requirements. RSA, however, is still widely used in legacy systems and offers broad compatibility. As ECC continues to grow in adoption, it is becoming the preferred cryptographic method in modern systems, especially those requiring efficiency and scalability, like IoT and mobile applications. Both RSA and ECC are not resistant to quantum attacks, and future cryptographic systems will need to transition to post-quantum algorithms to maintain security.

 

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