# All Questions

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### Is it overkill to run a key generated by OpenSSL through pbkdf2?

I'm generating a key & iv with OpenSSL via: ...
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### Which hardware-accelerated AES-GCM implementations support encryption in-place? [closed]

By encrypt in place I mean the following. Suppose I have an input plaintext of length L and I have also allocated an extra E bytes at the start and/or end of the buffer, with E << L. So the ...
187 views

### Key expiration policy for 3DES / TDES / Triple DES

I have a system that signs plain text messages using a message authentication code (MAC) encrypted with 3-key Triple DES. The short message is used on connection to establish a session key, so it ...
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I want to encrypt data and protect its integrity and confidentiality. However, I cannot increase the length of the data. Are there any cipher modes of operation which provide confidentiality and ...
1k views

### How to calculate the maximum output size for data encrypted with a RSA Private Key?

I have an an encryption algorithm I am working with that looks like this: prv_key_enc(sha1_hash(data)) Where, the RSA parameters are: RSA/ECB/PKCS1Padding 1024 ...
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### Is MITM possible after key exchange phase done successfully in RSA?

Is MITM attack theoretically possible after public/private key pair exchange is done successfully. Say Alice and Bob have genuine public keys of each other. Is MITM possible further during ...
296 views

### why inverse in diffie-hellman protocol will not give same value?

Security of diffie hellman protocol is $K=g^{ab}$.if sender want to calculate value of $b$(given $a$) he can do $g^{{{ab}^b}^{-1}}$(where K=$g^{ab}$) which will give $g^{a}$ as we are cancelling value ...
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### Random numbers for Master Key and Key_block

Exploration through RFCs concludes that random numbers used in the creation of Master Key and Key Block(Key material for Encryption Key and Mac Secret) are from ServerHello.random and ...
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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 ...
73 views

### SHA-256 Wrong registers

I have a problem with my sha256 java implementation. The registers (a…h) are correct until j=24; ...
214 views

### Why is “multiplying” $g^x$ and $g^y$ not possible?

The computational Diffie-Hellman problem states that for a cyclic group $G$ of order $p$ and a generator $g$, it is hard to find the value $g^{xy}$ given only $g^x$ and $g^y$ (but easy if either $x$ ...
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### Unpredictability vs randomness

I'm experimenting with creating an entropy source for an environment where I have no hardware available and the language is very high level (executed in a virtual machine). I know it's not a good idea ...