Skip to main content

Questions tagged [kerberos]

Kerberos is a computer network authentication protocol which allows nodes communicating over a non-secure network to prove their identity to one another in a secure manner.

Filter by
Sorted by
Tagged with
1 vote
0 answers

In Kerberos, is the "Authentication Server" the only "Trusted Third Party"? Or is "Ticket Granting Server" also a "Trusted Third Party"? [closed]

I know that AS (Authentication Server) is a TTP (Trusted Third Party) because it generates keys for two entities (for the client and the TGS). But what about TGS (Ticket Granting Server)? It also ...
allexj's user avatar
  • 51
3 votes
1 answer

Hashed Password Kerberos PKDF2 AES - ActiveDirectory

I know that in Active Directory environments passwords are stored in the form of hashes depending on encryption types used in the environment. I understand also that when using AES as a symmetric ...
Matías Huartamendía's user avatar
0 votes
1 answer

Derrive a new key from Trusted Third Party (e.g. Kerberos) session key

Kerberos (and I assume other Trusted Third Party protocols) use (hash) an existing shared secret key to create a session key used for authentication. I read that this authentication secret key can ...
Elliot's user avatar
  • 3
0 votes
1 answer

Why are des-cbc-hmac and rc4-hmac-exp considered weak in kerberos?

Kerberos uses des-cbc-hmac (mac and encrypt) and rc4-hmac-exp based on md5 (mac and encrypt I think) in their encryptions. Those encryptions are considered as weak and should not be used. Why are they ...
adi's user avatar
  • 175
0 votes
1 answer

What authenticated encryption do kerberos use in windows?

I have learned about the kerberos protocol and seen that the windows version uses a couple of authenticated encryption schemas (like rc4-hmac-md5). What type of authenticated encryption is it? Is it a:...
adi's user avatar
  • 175
3 votes
0 answers

Why Kerberos isn't using Diffie-Hellman key exchange?

Kerberos transforms the user password to obtain a secret key, which is also stored in the kerberos database. That way what travels through the network is the derived key, not the password itself, ...
Bozho's user avatar
  • 171
1 vote
0 answers

Kerberos Use of SHA-1

A lot of good information on Kerbero's encryption methods discussed here, but I there is a second question that arises. Does use of SHA-1 in the overall algorithm weaken Kerberos? If so, will ...
PrometheusRising's user avatar
1 vote
0 answers

Why isn't Kerberos using temporary keys to avoid dictionary attacks?

In the Kerberos protocol, the user sends his ID, the server (Or ticket granting server) ID and a nonce value. The Key Distribution Center uses a key (I assume symmetrical) derived from the client's ...
asaf92's user avatar
  • 121
1 vote
0 answers

Break an encryption made with XOR of a key and a known Nonce

My questions is general, but in my case regards the Kerberos protocol and the communication between the client first message and the KDC. Is there some problem in encrypting using a: (secret key XOR ...
Oron Werner's user avatar
1 vote
0 answers

Known plain-text attack on Kerberos

This is a form of the Kerberos protocol I have two questions. Why does this protocol give the opportunity of a known plain-text attack because of no authentication of Joe? And how would an attacker ...
nmq's user avatar
  • 11
0 votes
1 answer

Use exported certificate with private key to logon using Kerberos

First I just would like to mention, that my knowledge in windows authentification methods are very limited. So my question: Is it possible to use custom credential provider in windows to log on, that ...
Theodor's user avatar
2 votes
1 answer

Protocol that generates keys every 2 minutes using KDC

I am using a Key Distributed Center (KDC) and a key distribution protocol such as Kerberos. In order to limit the amount of ciphertext produced with the same key, I want to renew the session keys ...
CXB's user avatar
  • 321
1 vote
0 answers

What is the DK function when generating an AES key for Kerberos 5?

I'm trying to understand RFC3962. So far I understood everything, except for the last part: generating the derived key from the PBKDF2 output. To generate an encryption key from a pass phrase and ...
Thomas Wagenaar's user avatar
1 vote
0 answers

Hiding the identity of a party within the Kerberos authentication scheme

In the Kerberos authentication protocol, as described here: would it be safer to replace step (1) with: $$ A \rightarrow T : A, E_{K_A{_{T}}}(B, N_A) $$ so that a passive adversary does not know ...
Sebi's user avatar
  • 281
7 votes
1 answer

What does AES256-CTS-HMAC-SHA1-96 mean in relation to Kerberos?

I'm not completely clueless as to what it means, but I'd like to understand it at a higher level. The highest encryption type used by Active Directory domain controllers for Kerberos authentication ...
Ryan Ries's user avatar
  • 173
3 votes
2 answers

What is sent on the initial communication with Kerberos?

When a user wants to communicate with another user (let's say Alice and Bob), what is sent over the network during the initial communication? Alice uses her Kerberos client and enters her password ...
Lucas Kauffman's user avatar