1.2. We received the following ciphertext which was encoded with a shift cipher: xultpaajcxitltlxaarpjhtiwtgxktghidhipxc

[answerhappygod]

1.2. We received thefollowing ciphertext which was encoded with a shiftcipher: xultpaajcxitltlxaarpjhtiwtgxktghidhipxciwtvgtpilpit
ghlxiwiwtxgqadds.
1.3. We consider thelong-term security of the Advanced Encryption Standard (AES) with akey length of 128-bit with respect to exhaustive key-searchattacks. AES is perhaps the most widely used symmetric cipher atthis time.
1. Assume that an attacker has a special purpose applicationspecific integrated cir- cuit (ASIC) which checks5 · 108 keys per second, and she has a budget of $1million. One ASIC costs $50, and we assume 100% overhead forintegrating the ASIC (manufacturing the printed circuitboards, power supply, cooling, etc.). How many ASICs can we run inparallel with the given budget? How long does an average key searchtake? Relate this time to the age of the Universe, which is about1010 years.
2. We try now to take advances in computer technology intoaccount. Predicting the future tends to be tricky but the estimateusually applied is Moore’s Law, which states that the computerpower doubles every 18 months while the costs of integratedcircuits stay constant. How many years do we have to wait until akey-search machine can be built for breaking AES with 128 bit withan average search time of 24 hours? Again, assume a budget of $1million (do not take inflation into account).
1.4. We now consider therelation between passwords and key size. For this purpose weconsider a cryptosystem where the user enters a key in the form ofa password.
stead of the full 7 bits of theASCII-encoding. What is the corresponding key
length in bits in this case?
key length of 128 bits in case ofletters consisting of
a. 7-bit characters?b. 26 lowercase letters from the alphabet?