Design of cryptographic protocols, i.e. ways of using algorithms (primitives) to achieve one or more security goals like integrity, confidentiality, authenticity (maybe together with non-security-related goals). If you ask about a specific protocol, tag with its name instead (or additionally, if ...
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Combatting traffic shape analysis with spurious packets
I was reading a question about combatting traffic analysis, and a thought occured. If I send random junk messages periodically, would that defeat traffic analysis?
The messages would contain some ...
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2answers
132 views
Untraceable communication protocol
I am doing a research about secure communication protocols.
I would be interested to know whether a protocol exists such that it grants that the two end-points taking part to the communication cannot ...
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1answer
414 views
Is this design of client side encryption secure?
I want to build a secure file storage web application. Users should be sure that server doesn't know how to decrypt files so encryption should take place at client side (i.e. in Javascript) and TLS ...
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92 views
Setting protocol parameters to achieve concrete security
Background
One issue with modern security proofs is that they are usually asymptotic. In other words, such proofs are usually formulated as follows: For any polynomial-time adversary $\mathcal A$, we ...
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651 views
Use of nonces in Kerberos and Needham–Schroeder protocols
Can you please explain me what is the reason of using nonces in the Needham-Schroeder and in the Kerberos protocols for Key Transport.
In particular :
Can you explain me the use of $N_A$?
And ...
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2answers
92 views
Distinguishing Encryption Methods from the Output
Suppose that you see all IP communication packets between two computers for a day, as they pass through a connecting router, and this amounts to 10MB. You additionally know that all data transmission ...
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386 views
Is this password migration strategy secure?
I want to upgrade the security of some existing databases of users' authentication tokens strictly for the purpose of making sure that if the database is stolen, attackers will not be able to guess ...
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2answers
84 views
How can I protect against the failure of a block or symmetric cipher?
Can I protect against the failure of a block or symmetric cipher by chaining different techniques together? If so what implementation details should I be aware of?
Are some combination of ciphers ...
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1answer
254 views
Replay attack prevention under strict conditions
Say I have a request-response protocol and the task to make it immune to replay attacks. The requirements are as follows:
The defense mechanism cannot rely on the clocks of the parties.
The defense ...
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58 views
Cryptographic Algorithm/Protocol needed
I am trying to achieve the following:
Encrypted files are stored on users filesystem. The user uses my client to authenticate against a server. Once he is authenticated successfully he gets a token ...
