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Maarten Bodewes ♦
Maarten Bodewes ♦
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I've been taking a crypto course online. I have a good idea how PRG's and Stream Ciphers work, but I'd love to get some input to help visualize what is actually happening. I understand a seed is used, then expanded into a keyspace. Is this correct?

So: G: {0,1}^s -> {0,1}^n , n >> s$G: \{0,1\}^s \to \{0,1\}^n , n \verb|>>| s$

From what I understand.. For a generator (Function Gfunction $G$) a random seed from all s$s$ bit seedspace is mapped to an n$n$ bit string.

The thing i'mI'm having trouble conceptualizing is the "mapping" of the random seed to the key (I might be totally incorrect with the way i'mI'm phrasing this). Is this process laid out in the actual cipher (e.g., CSS, Salsa20) or there something else going on?

I've been taking a crypto course online. I have a good idea how PRG's and Stream Ciphers work, but I'd love to get some input to help visualize what is actually happening. I understand a seed is used, then expanded into a keyspace. Is this correct?

So: G: {0,1}^s -> {0,1}^n , n >> s

From what I understand.. For a generator (Function G) a random seed from all s bit seedspace is mapped to an n bit string.

The thing i'm having trouble conceptualizing is the "mapping" of the random seed to the key (I might be totally incorrect with the way i'm phrasing this). Is this process laid out in the actual cipher (e.g., CSS, Salsa20) or there something else going on?

I've been taking a crypto course online. I have a good idea how PRG's and Stream Ciphers work, but I'd love to get some input to help visualize what is actually happening. I understand a seed is used, then expanded into a keyspace. Is this correct?

So: $G: \{0,1\}^s \to \{0,1\}^n , n \verb|>>| s$

From what I understand.. For a generator (function $G$) a random seed from all $s$ bit seedspace is mapped to an $n$ bit string.

I'm having trouble conceptualizing is the "mapping" of the random seed to the key (I might be totally incorrect with the way I'm phrasing this). Is this process laid out in the actual cipher (e.g., CSS, Salsa20) or there something else going on?

Tweeted twitter.com/#!/StackCrypto/status/512303091975458816
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Aaron Tracy
Aaron Tracy
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Understanding Pseudo Random Generators

I've been taking a crypto course online. I have a good idea how PRG's and Stream Ciphers work, but I'd love to get some input to help visualize what is actually happening. I understand a seed is used, then expanded into a keyspace. Is this correct?

So: G: {0,1}^s -> {0,1}^n , n >> s

From what I understand.. For a generator (Function G) a random seed from all s bit seedspace is mapped to an n bit string.

The thing i'm having trouble conceptualizing is the "mapping" of the random seed to the key (I might be totally incorrect with the way i'm phrasing this). Is this process laid out in the actual cipher (e.g., CSS, Salsa20) or there something else going on?