Computerphile diffie hellman

1. What is Diffie-Hellman vulnerability?
2. What is Diffie-Hellman encryption?
3. What is the Diffie-Hellman algorithm used for?
4. Why is Diffie-Hellman better than RSA?
5. How safe is Diffie-Hellman?
6. Can Diffie-Hellman be decrypted?
7. Is TLS a Diffie-Hellman?
8. Is Diffie-Hellman public or private key?
9. Why D-H is used in VPN?
10. What is Diffie-Hellman formula?
11. Why Diffie-Hellman cannot be used for digital signature?
12. What is a limitation weakness of Diffie Hellman key exchange?
13. What is the advantage of Diffie-Hellman?
14. Can Diffie-Hellman be cracked?
15. Can Diffie-Hellman be broken by a quantum computer?
16. Has Diffie-Hellman been cracked?
17. What are Diffie-Hellman's weaknesses?
18. What attacks are possible on Diffie-Hellman?
19. What is the different Hellman key exchange vulnerable to?
20. What is the problem in Diffie-Hellman key exchange protocol?
21. Can Diffie-Hellman be cracked?
22. What is the most secure DH group?
23. Does TLS use RSA or DH?
24. Can Diffie-Hellman be broken by a quantum computer?
25. How do you break Diffie-Hellman?
26. How long does it take to break Diffie-Hellman?
27. What are the 3 types of encryption keys?
28. Is DH symmetric or asymmetric?

What is Diffie-Hellman vulnerability?

The Logjam vulnerability is a weakness that left secure sites open to attack. A weakness in encryption protocol called Diffie-Hellman is letting attackers downgrade certain connections to 512-bits of security which is low enough to be cracked by attackers.

What is Diffie-Hellman encryption?

Diffie-Hellman key exchange is a method of digital encryption that securely exchanges cryptographic keys between two parties over a public channel without their conversation being transmitted over the internet. The two parties use symmetric cryptography to encrypt and decrypt their messages.

What is the Diffie-Hellman algorithm used for?

The Diffie-Hellman algorithm will be used to establish a secure communication channel. This channel is used by the systems to exchange a private key. This private key is then used to do symmetric encryption between the two systems.

Why is Diffie-Hellman better than RSA?

RSA is used to exchange keys for asymmetric encryption while Diffie-Hellman is used for sharing the keys for symmetric encryption. Ephemeral Keys: Generating keys for each and every session(Ephemeral keys) in RSA is extremely difficult opposed to Diffie-Hellman, which provides an extremely easy generation of keys.

How safe is Diffie-Hellman?

While the Diffie-Hellman key exchange may seem complex, it is a fundamental part of securely exchanging data online. As long as it is implemented alongside an appropriate authentication method and the numbers have been selected properly, it is not considered vulnerable to attack.

Can Diffie-Hellman be decrypted?

The session key is encrypted. But if the attacker ever gets the secret session key, then they can also decrypt the encrypted data. The Diffie-Hellman method is unique because it is not the secret session key that is transmitted but only the result of an arithmetic operation.

Is TLS a Diffie-Hellman?

One family of encryption cipher suites used in TLS uses Diffie-Hellman key exchange.

Is Diffie-Hellman public or private key?

Both RSA and Diffie Hellman (DH) are public-key encryption protocols used for secure key exchange. They are independent protocols that do not rely on one another.

Why D-H is used in VPN?

It allows two parties to establish a shared secret key used by encryption algorithms (DES or MD5, for example) over an insecure communications channel. D-H is used within IKE (described later in this article) to establish session keys.

What is Diffie-Hellman formula?

The formula to calculate the key is K = (Yb)Xa mod q. For the receiver, you need the private key (Ya), sender's public key (Xb), and the original q. The formula to calculate the secret key is K = (Ya)Xb mod q. If both the values of K generated are equal, the Diffie-Hellman key exchange algorithm is complete.

Why Diffie-Hellman cannot be used for digital signature?

This works fairly well as an encryption primitive, however because this random number is used as a symmetric key, it doesn't provide any non-malleability properties (because the attacker can see that symmetric key; it would be used during the signature verification). Save this answer.

What is a limitation weakness of Diffie Hellman key exchange?

Disadvantages of the Diffie Hellman Algorithm

The algorithm can not be sued for any asymmetric key exchange. Similarly, it can not be used for signing digital signatures. Since it doesn't authenticate any party in the transmission, the Diffie Hellman key exchange is susceptible to a man-in-the-middle attack.

What is the advantage of Diffie-Hellman?

The Diffie–Hellman (DH) Algorithm is a key-exchange protocol that enables two parties communicating over public channel to establish a mutual secret without it being transmitted over the Internet. DH enables the two to use a public key to encrypt and decrypt their conversation or data using symmetric cryptography.

Can Diffie-Hellman be cracked?

To attack a Diffie-Hellman key exchange, one could extract the secret key a from one of the peer's public key ya = g a (mod p). One could then compute the shared key g ab (mod p) using the other peer's public key yb = g b (mod p). This would work, however it requires to isolate the exponent from the formula to work.

Can Diffie-Hellman be broken by a quantum computer?

And, it turns out that solving factoring and discrete logarithms (and therefore breaking RSA, Diffie-Hellman and Elliptic-Curve public-key algorithms) are not hard for such machines. Stated differently, all three of these algorithms are broken by a quantum computer of sufficient size.

Has Diffie-Hellman been cracked?

Relax—it's not true that researchers have broken the Diffie-Hellman key exchange protocol.

What are Diffie-Hellman's weaknesses?

Limitations of Diffie-Hellman

It cannot be used for asymmetric exchange. It cannot be used to encrypt messages.

What attacks are possible on Diffie-Hellman?

In this attack, the attacker tries to stop the communication happening between sender and receiver and attacker can do this by deleting messages or by confusing the parties with miscommunication. Some more attacks like Insider attack, Outsider attack, etc are possible on Diffie-Hellman.

What is the different Hellman key exchange vulnerable to?

The Diffie-Hellman key exchange is vulnerable to a man-in-the-middle attack. In this attack, an opponent Carol intercepts Alice's public value and sends her own public value to Bob. When Bob transmits his public value, Carol substitutes it with her own and sends it to Alice.

What is the problem in Diffie-Hellman key exchange protocol?

Diffie-Hellman does have a weakness: If an intruder Charlie can intercept and resend email between Alice and Bob, then the intruder can pretend to be Bob for Alice and pretend to be Alice for Bob, substituting his own y_C and tricking each of Alice and Bob into having a shared secret key with him.

Can Diffie-Hellman be cracked?

To attack a Diffie-Hellman key exchange, one could extract the secret key a from one of the peer's public key ya = g a (mod p). One could then compute the shared key g ab (mod p) using the other peer's public key yb = g b (mod p). This would work, however it requires to isolate the exponent from the formula to work.

What is the most secure DH group?

DH group 1 consists of a 768 bit key, group 2 consists of 1024 bit key, group 5 is 1536 bit key length and group 14 is 2048 bit key length. Group 14 is the strongest and most secure of the ones just mentioned, but there are other key lengths as well.

Does TLS use RSA or DH?

There are two popular TLS key-exchange methods: RSA and DH . In either case, the typical TLS Handshake looks like this: Client sends a ClientHello message which contains the maximum TLS version that it supports and a list of cipher suite in the order of preferences.

Can Diffie-Hellman be broken by a quantum computer?

And, it turns out that solving factoring and discrete logarithms (and therefore breaking RSA, Diffie-Hellman and Elliptic-Curve public-key algorithms) are not hard for such machines. Stated differently, all three of these algorithms are broken by a quantum computer of sufficient size.

How do you break Diffie-Hellman?

To attack a Diffie-Hellman key exchange, one could extract the secret key a from one of the peer's public key ya = ga (mod p). One could then compute the shared key gab (mod p) using the other peer's public key yb = gb (mod p).

How long does it take to break Diffie-Hellman?

Security Threat of the Diffie-Hellman

If p and g have thousands of bits, then the best-known algorithms to compute discrete logs, although faster than plain brute force, will still take millions of years to compute.

What are the 3 types of encryption keys?

Symmetric, or secret key encryption, uses a single key for both encryption and decryption. Symmetric key encryption is used for encrypting large amounts of data efficiently. 256-bit AES keys are symmetric keys. Asymmetric, or public/private encryption, uses a pair of keys.

Is DH symmetric or asymmetric?

DH is not a symmetric algorithm – it is an asymmetric algorithm used to establish a shared secret for a symmetric key algorithm.