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I am considering how long a SHA-1 computation will need on modern CPU/GPU's. Just in case we are interested in brute forcing and consider the birthday paradoxon, then we need consider the SHA-1 output range of 160 (?) Bits.

The number of brute force attempts, until our attack is by 50% successful, requires $\left\lceil 1.18\cdot \sqrt{2^{160}} \right\rceil \sim 1.43 \cdot 10^{24}$ attemptions. How long would, say Intel's i3/5/7, require until this computations and comparisons are done?

The measure should be given in time per mega byte.

Shalec
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1 Answers1

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SHA-1 runs at 2.24 cpb on an AMD Ryzen 1700 (at 2994MHz) for somewhat short messages (ie 576 bytes) which is a very relevant number given that you don't want to hash large messages, but many messages.

So for the full message you need a little less than 1300 cycles. So now suppose we have an optimized architecture / shorter messages and get this down to 1000 cycles per attempt.

You can now compute the speed yourself. In this case a Ryzen achieves $$8\cdot 2994\cdot 10^6/10^3\approx 24\cdot 10^6$$ attempts per second, that is, 24 million.

SEJPM
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