The Big Debate, 2048 vs. 4096, Yubico’s Position (2024)

FAQs

The Big Debate, 2048 vs. 4096, Yubico’s Position? ›

While it is true that a longer key provides better security, we have shown that by doubling the length of the key from 2048 to 4096, the increase in bits of security is only 18, a mere 16%. Moreover, besides requiring more storage, longer keys also translate into increased CPU usage and higher power consumption.

A 4096 bit key does provide a reasonable increase in strength over a 2048 bit key, and according to the GNFS complexity, encryption strength doesn't drop off after 2048 bits. There's a significant increase in CPU usage for the brief time of handshaking as a result of a 4096 bit key.

The difference between RSA 2048 and RSA 4096 lies in their bit length, with RSA 2048 being 2048 bits long and RSA 4096 doubling that at 4096 bits, offering enhanced security at the cost of increased processing time. NIST deems RSA 2048 sufficient until 2030, balancing security strength and computational efficiency.

The case for using 4096 bits

If an attack is found that allows a 2048 bit key to be hacked in 100 hours, that does not imply that a 4096 bit key can be hacked in 200 hours. The hack that breaks a 2048 bit key in 100 hours may still need many years to crack a single 4096 bit key.

RSA keys are typically 1024- or 2048-bits long, but experts believe that 1024-bit keys are no longer fully secure against all attacks. This is why the government and some industries are moving to a minimum key length of 2048-bits.

With the world's fastest supercomputers, it would take around 300 trillion years to break the 2048-bit RSA encryption. A quantum computer would be finished with a similar task in merely eight hours.

As of 2022, AI achieved over 95% (likely over 98%, but the measurement has noise) probability of making a 16384 tile, over 75% (likely over 80%) probability of making a 32768, and over 3% probability of making a 65536 (improving over the results in previous papers).

RSA-4096 is a legitimate encryption cipher. It is one of the best encryption systems that you can use to protect your data in transmission. But, unfortunately, a system that is universally available can be used by miscreants as well as honest business people.

ED25519 is generally considered more secure and efficient than RSA, while RSA provides a higher level of security due to its larger key size. The choice between these two algorithms depends on the specific application and the level of security and efficiency required.

Over time, new TLS versions are developed, and some of the previous versions become outdated for vulnerabilities or technical reasons; and, therefore, should no longer be used to protect data. TLS 1.2 or TLS 1.3 should be used, and any organizations should not use SSL 2.0, SSL 3.0, TLS 1.0, and TLS 1.1.

Why is RSA so hard to break? ›

The security of RSA depends on the fact that it is extremely difficult to factorize large numbers with many digits into their prime factors, even with the most powerful computers available today.

Outsiders only know r and n, but they do not know p and q, even though they know the product n=p*q. So outsiders have no easy way of computing (p-1)(q-1). Finding p and q amounts to factoring the number n that you were given.

Quantum basics

So far, all experts have agreed that a quantum computer large enough to crack RSA would probably be built no sooner than around a few dozen decades.

According to the recommendation of the National Institute of Standards and Technology (NIST), the smallest RSA key size that can be considered secure is 2,048 bits. This means approximately 600 digits, but in many cases larger keys of 3,072 or 4,096 bits are also used.

"Breaking RSA is usually attempted by using Shor's algorithm in a quantum computer but there are no quantum computers in existence that can produce enough gates to implement Shor's algorithm that would break 2048 keys," Woodward said.

Alan Woodward, a professor of computer science at the University of Surrey, told BankInfoSecurity that no quantum computer in existence has enough gates to implement Shor's algorithm and break RSA-2048.

Select a key size for your generated certificate and keys. Certificates with 2048-bit keys last one year and are faster than certificates with 4096-bit keys. Certificates with 4096-bit keys last two years. Note After you save a Salesforce certificate, you can't change its type or key size.

Diffie-Hellman (DH) Key Exchange: • For modern applications, a minimum of 2048-bit is recommended, but 3072-bit or 4096-bit is becoming more common for stronger security. 4. Elliptic Curve Cryptography (ECC): • ECC offers equivalent security with shorter key lengths compared to traditional algorithms.

The advantage of 2048-bit encryption is increased strength. By strength we mean its ability to resist brute force attacks. A brute force attack is one that simply tries all of the possible keys until the correct one is found.

The most common methods are assumed to be weak against sufficiently powerful quantum computers in the future. Since 2015, NIST recommends a minimum of 2048-bit keys for RSA, an update to the widely-accepted recommendation of a 1024-bit minimum since at least 2002.