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Questions tagged [transport-security]

Transport security about establishing a real time secure channel from a sender to a receiver. Transport security generally requires more protection and a more intricate protocol than securing data at rest. Well known attacks against transport protocols include MitM attacks and CBC padding oracle attacks.

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why do we asume that in the registration process communication is over the secure channel?

I was reading some research papers and saw that in Registration phase/process it is always assumed that communication is over the secure/private channel, whereas, all of the phases communication is ...
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197 views

What is Perfect forward secrecy?

I have read that when a user contacts an entity like a bank, it creates a pre-master key and then selects a master key for subsequent communications. Can the lack of PFS, create a security flaw if ...
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50 views

Does it make sense to have long SSH Key with shorter Passphrase?

If we encrypt our data with a longer SSH key which is protected by a shorter passphrase (with a decent entropy), then the limiting factor is entropy of the passphrase. So why do we use a longer key at ...
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152 views

Key transport vs key encapsulation?

What exactly is the difference between key transport and key encapsulation? Either they seem to be used interchangeably, either I'm mixing stuff up.
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70 views

Secure communication channel recommendations

I'm working on a cryptography-related project, which uses ECC (elliptic curve cryptography). And one of the things that I need is a "secure" communication channel for two entities. I need someone to ...
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1answer
125 views

Establishing a shared secret over a unsecure channel

Is it possible to establish a shared secret between two devices if the devices have no prior knowledge and no secondary secure channel to exchange information? Assume a Dolev–Yao model for the ...
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1answer
168 views

TLS: Risks of using a NULL cipher with encryption implemented in application?

We have a browser-launched JNLP/WebStart application that is no longer able to establish client-server CORBA/IIOP communications across TLS 1.0/1.1 due to relying on a cipher suite that uses an ...
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39 views

Is there anything out to generate certificates using VXEdDSA?

As the title says - Is there anything out to generate certificates using VXEdDSA? And if there isn't what options do I have for hardening security on tls 1.3 with ed25519 certificate so that a ...
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1answer
222 views

Signal Double Ratchet - How can Alice send 2+ messages in the beginning of the Signal Protocol?

I'm studying about Signal Protocol and I had a doubt in Double Ratchet Algorithm. This section describes how to derive the receiving and sending key messages. Alice is initialized by Bob public ...
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1answer
176 views

X3DH Protocol - How can the receiver calculate the Shared Key?

I'm reading about Signal Protocol and X3DH Protocol. In the X3DH Protocol, Alice sends a initial message to Bob encrypted with a Shared Key(SK). This SK is calculated using (this section): ...
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1answer
106 views

There is a protocol similar to SRP but where a part of the secret is stored on the client side?

SRP is very useful but if our DB is leaked, an attacker could brute force a user's password with his associated salt/verifier found in the DB. I'm searching a solution to prevent this. My first idea ...
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2answers
704 views

X3DH protocol - What are One-time prekeys for?

I'm reading about Signal Protocol and this protocol uses the X3DH Protocol to establish a shared secret key between the two parties but I couldn't understand why we use one-time prekeys in the flow. ...
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1answer
65 views

Is there an escrow-like mechanism that doesn't involve a trusted 3rd party?

We know that escrow mechanisms are easy to implement when it involves a trusted 3rd party. For example if A and B don't trust each other they can simply send their goods to C whom they both trust. ...
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What's a good security schema for many to many communication?

Assuming you have a "typical" group chat-room, with n participants connected together by a server (the server handles message routing). Would be a good security schema which would allow for encrypted ...
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2answers
393 views

TLS Finished message: is it MAC or HMAC

In several academic literature, the term Finished MACs is used frequently. I wonder, is it really a MAC or HMAC? I am looking at literature in TLS 1.2 vs. TLS 1.2 specs. The specs of TLS 1.2 Finished ...
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1answer
697 views

TLS1.3 encrypted handshake

I read that TLS 1.3 supports encrypted handshake. Is it achieved using encrypted_extensions? Does it mean that the records which contains handshake messages are encrypted/protected from the point of ...
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1answer
380 views

What's dh-composite test on badssl.com?

The site badssl.com provides examples of bad (red icon) and good (green icon) uses of TLS for the purpose of testing TLS implementations. I'm a bit confused by the test called dh-composite. This ...
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4answers
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Best choice out of these six TLS cipher suites

I have a small embedded platform that supports 6 TLS ciphers. Is there a good/better/best one to chose? I was looking around on the web for some kind of rating system or list of ciphers that have ...
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1answer
75 views

Any case that can require to encrypt a certificate revocation list before distribution

As far as we know certificate revocation lists (CRLs) include public information so they do not have to be encrypted before distribution. Is there a case that can require to encrypt it before ...
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0answers
25 views

How deriving the session keys from master key are more secure than deriving them from pre-master key? [duplicate]

How deriving the session keys from master key are more secure than deriving them from pre-master key? If a person in middle is sniffing the whole communication, can he generate pre-master key also?
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Dtls 1.2: Client Hello extension “use_srtp”

I am implementing DTLS-SRTP, i have a question about client hello extension "use_srtp". In my case in this extension client hello send "00 04 00 01 00 02 00" According to RFC 5764 https://tools.ietf....
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3answers
197 views

DIY message level security?

This might be in danger of being too elementary a question for this community but I'm hoping for expert help: Assuming that TLS is not enough to protect messages transmitted between a client and a ...
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1answer
112 views

Insecure third party connection

My organization processes some PII data and shares it with an outbound connection (outflow only) that is a third party. The data transfer transactions occur without human intervention. That outbound ...
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0answers
118 views

DTLS 1.2 Finished message

I am implementing DTLS 1.2 and using ECDHE_RSA_AES_128_GCM_SHA256 cipher suit. Below is my client finished message Can anyone explain this message? How many bytes for verify data? Is there ...
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110 views

signature, hashing schemes

I have 20 friends. we create message(s) (1...i) and tar them up with a file messages.hashes(1..i). We sign these tars with our ...
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2answers
110 views

Which encryption is recommended for own messenger [closed]

I wrote my own messaging-app and now I would like to encrypt the data transfer between my client (app) and my server. What kind of encryption is easy to implement and can be recommended? I am very ...
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What is the current encryption method used on GSM currently?

I am currently doing a mini project which sniffs GSM packets using gr-gsm and wireshark. I was wondering if anyone knows what is the name of the current encryption algorithm method used on GSM?
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4answers
830 views

Are there any practical ways to transfer random data securely?

The owner of the random.org service recommends that you do not use randomly generated numbers from their website in cryptographic keys. This makes sense, but it got me wondering. Is it possible to ...
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5answers
2k views

What is the most secure ECC Curve?

I have for a while used Koblitz curve (sect571k1), in ECDH and ECDSA. But I have started wonder if it is the most secure. I prefer security over efficiency. So the curve doesn't have to be the most ...
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0answers
535 views

Why is SSL/TLS so complicated? [closed]

I'm new to SSL/TLS and I'm staring as a new security researcher. It appears to me that SSL/TLS protocol is needlessly complex for arriving at a shared secret. The complexity results in so many bugs (e....
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1answer
44 views

What communications security protocols exist that aren't based on PKC?

Lets say that you have two devices that need to communicate in a secure manner. These devices can share secrets before communication takes place (This sharing of secrets occurs over another secure ...
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2answers
124 views

Initializing PGP keys by one side

I am using a PGP method to encrypt and decrypt messages shared between users A and B. Upon the start of a message exchange is the initialization of the public and secret keys by both Users. Lets say ...
3
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1answer
420 views

Do ECDH and ECDSA combined solution provide an authenticated protocol exchange solution in MCU environment?

I'm working on a project in MCU (micro controller) environment with GPRS connection to exchange data securely with the cloud. The encryption algorithm has been selected to use AES. I did some search ...
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2answers
535 views

Secure Channel - Encryption and Decryption Keys For A Message

I'm currently reading Cryptography Engineering and in Chapter 7, the topic of secure channel is discussed. The channel described is using CTR for encryption. Below I include images with pseudo-code ...
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2answers
653 views

Shamir's secret sharing scheme - type of channels

For information theoretic security in Shamir's [m,m] secret sharing scheme, do i need both authentic and confidential channels? Another related query is ;is it true that if the channels are only ...
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1answer
195 views

Secure Broadcast Channel

I've read a paper that says that one of the "assumptions" that it makes is secure broadcast. Why is this an assumption? Can't a broadcast channel be built with simple primitives--i.e. encrypt and sign ...
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1answer
212 views

Creating a secure key

Imagine that your lecturer and the undergraduate office have conducted a key exchange protocol after which both of them hold the string $X$. Yet, it is possible that a curious student sitting next to ...
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1answer
39k views

What is the “shared secret” used for in IPSec VPN?

Can somebody explain what the "shared secret" and "password" do when opening/creating a VPN tunnel? In this specific case I setup a VPN to my Fritz!Box and I had to provide a shared secret (which was ...
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2answers
259 views

Security of CFB on a public channel

Given a server that broadcasts all received data to all connected peers (except the sender), two participants can have an encrypted conversation using a self-synchronizing method like CFB and some ...
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3answers
415 views

Secure communication between multiple peers on a public channel

I am wondering how can I secure communications between multiple peers over a public channel, like an IRC channel. With two peers it is easy - they exchange their encryption keys and decrypt the ...