This new cipher is a Caesar Cipher with a twist. This cryptosystem will operate on bytes (8-bits): for an alphabet of 256 values (0255). Text will be represented as ASCII (A is represented by hex 0x41, etc.). Instead of shift, Exclusive OR (XOR) is used. Because of this, encryption and decryption are the same operation. ciphertext:

y8LT08LVh9PIh+TGwtTG1ZyHz8KHxsPRztTC1IfPzsqH08iH18 LVwcjVyofPztSHzcjS1cnC3ofQxtXOy96ch8/Ch9DVztPC1IfO yYfTz8KHy8LT08LVh9PPxtOH08/Ch8LJwsreh8/Gw4fDwtfG1d PCw4fGycOHz8bDh9PS1cnCw4fTz8LO1YfCydPO1cKHwcjVxMKH xsDGzsnU04fPzsqJh/DPwsmH08/O1IfLwtPTwtWH0MbUh8XVyN LAz9OH08iHz87Kh8bFyNLTh9PPwofKzsPDy8KHyMGH08/Ch8nO wM/Ti4fkxsLUxtWHxtfX1c7UwtSHz87Uh9TIy8POwtXUh8jBh8 7T1IfEyMnTwsnT1IuHxsnDh87J1NfO1cLUh9PPwsqH0M7Tz4fE yNLVxsDCh8HI1YfBzsDP087JwJ2H08/Ch8HIy8vI0M7JwIfDxt 6Lh8bTh9PPwofDxtDJi4fPwofKyNHC1IfPztSHxMbK14uHxsnD i4fPxtHOycCH19XIxMLCw8LDh8HI0tWHys7LwtSLh8/Ch8LU18 7C1IfTz8KHwcjVxMLUh8jBh9PPwofCycLK3ofIyYfTz8KHyNPP wtWH1M7DwofIwYfGh8TIydTOw8LVxsXLwofRxsvLwt6HxsnDh9 XO0dLLwtOJh+7Th9DG1IfGyYfGwcHGztWHyMGHwNXCxtOHw8bJ wMLVh9PIh8HOwM/Th9DO08+H1NLEz4fLxtXAwofByNXEwtSHzs mHxofDztTGw9HGydPGwMLI0tSH1M7T0sbTzsjJiYfhyNWH08/C h9fVwtTCydOLh9PPwtXCwcjVwouHzsnG1MrSxM+HxtSHz8KHzM nC0IfTz8bTh+TOxMLVyIfQxtSH1cLLwsbUwsOHwdXIyofTz8KH xcvIxMzGw8KLh8bJw4fTz8jSwM/Th9PPxtOHz8KHys7Az9OLh8 jJh9PPxtOHxsTEyNLJ04uH1cLLxt+Hz87Uh9TXwsLDi4fPwofP xsvTwsOH08/C1cKHxsnDh8HI1dPOwc7C1IfGh8TGyteHzsmH08 /Ch8rI1NOHwcbRyNLVxsXLwofXyNTO087IyYfPwofExsmJh+bJ w4fTz87Ui4fTz8jSwM+HztOH0MbUh9TKxsvLh87Jh87T1MLLwY uH/NPPwtXCh8XCzsnA+ofUxMbVxMLL3oeQl5eXh8rCyYuHxsnD h9PPwtTCh9PIyIfQztPPyNLTh8XGwMDGwMKLh9TTzsvLh8Xeh9 PPwofJxtXVyNDJwtTUh8jBh9PPwofXxtTUxsDC1IuHz8KHxMjJ 09XGxNPUh8bUh8rSxM+HxtSHz8KHxMbJi4fQztPPh9PPztSHyM XNwsTTi4fTz8bTh8/Ch8rG3ofEyMrCh87J08iH08/Ch8DVwsbT wtTTh8TIydPCytfTh9DO08+H08/Ch8LJwsreiYfuyYfTz8KHys LGydDPzsvCi4fUxMjS09SHz8bRzsnAh8XCwsmH1MLJ04fOyYfG y8uHw87VwsTTzsjJ1IuHz8KHwt/Gys7JwtSHxd6H0M/G04fKyN TTh8TIydHCyc7CydOH18bTz4fPwofKzsDP04fE1cjU1IfTz8KH 0cbLy8Leia2t64lFJzPzz8bTh8PG3ouH1MvOwM/Th9TMztXKzt TPwtSHyMGHxMbRxsvV3ofPxtHOycCH08bMwsmH18vGxMKHycLG 1YfTz8KH1c7RwtWLh8XI08+HxtXKzsLUh8zC19OHzsmH08/Czt WHyNDJh9fI1M7TzsjJ1J2H08/Ch+DG0svUi4fFwsTG0tTCh9PP wt6H0MLVwofG0MbO087JwIfLxtXAwtWHwcjVxMLUh9DPzsTPh8 /Gw4fJyNOH08/CyYfG1dXO0cLDnIfkxsLUxtWLh/zTyIfUwsL6 h87Bh9fC1cTPxsnEwofF3ofX1cLTwsnEwofIwYfBwsbVh8/Ch8 TI0svDh8bLy9LVwofTz8KHwsnCyt6H08jQxtXD1IfPztSH18jU ztPOyMmLh9TIh9PPxtOHz8KHys7Az9OHwsnAxsDCh87Jh8XG09 PLwouHzsmHwdXIydOHyMGHz87Uh8TGyteLh8jJh9PPztSH1M7D wofIwYfTz8KH0cbLy8LenIfOwYfPwofEyNLLw4fJyNOHxsTEyM rXy87Uz4fTz87Ui4fTz8bTi4fPxtHOycCHzsnW0s7VwsOHxsXI 0tOH08/Ch9fG1NTC1IuHz8KHys7Az9OHxNXI1NSH08/Ch9HGy8 vC3ofGycOH08/Ch9XO0cLVh9DO08+H08/Ch8vC1NSHz8bdxtXD iYfm04fDxt6KxdXCxsyH08/Ch8TG0cbL1d6HyMGH08/Ch8LJws reh8bX19XIxsTPwtSH08iH08/Ch8TGyteHxsnDh83IzsnUh8XG 09PLwofQztPPh8jS1YfPyNXUwomH5MbC1MbVh8jVw8LV1IfTz8 KHz8jV1MKH08iHwM7RwofQxt6H19LV18jUwsvei4fGycOH1cLT 1cLG04fTyIfTz8KHxMbK152HxtOH08/Ch9TGysKH087KwofPwo fI1cPC1dSH08/Ch8TGyteH08iHxcKHwcjV087BzsLDh9DO08+H xofPzsDPwtWH1cbK18bV04fOyYfGy8uHw87VwsTTzsjJ1IuH08 /Ch8DG08LUh9PIh8XChw==

Your agents have found that the following Python 3 encryption algorithm (C and Java given later): import base64 00 von AWNA def encode(text): return base64.b64encode(text) def decode(text): return base64.b64decode(text) def encrypt(cleartext, key): to return = bytearray(len(cleartext)) for i in range( len(cleartext)): to_return[i] = cleartext[i] * key return bytes (to_return) Analysis of the encryption function shows that it can output non-printable characters (confirm this for yourself), therefore all output is encoded using Base64 Encoding using the encode and decode functions. For example, the string test encrypted with the key 0x80 (128 decimal) is: 1 2 print(encode(encrypt(b"test", 0x80))) b'90Xz9A==" We can verify that encrypting 90X29A== with the key 0x80 results is "test": i 2 print(encrypt(decode("90Xz9A=="), 0x80)); b'test' Your spies have also converted this code to a Java class and C code. Your agents have found that the following Python 3 encryption algorithm (C and Java given later): import base64 00 von AWNA def encode(text): return base64.b64encode(text) def decode(text): return base64.b64decode(text) def encrypt(cleartext, key): to return = bytearray(len(cleartext)) for i in range( len(cleartext)): to_return[i] = cleartext[i] * key return bytes (to_return) Analysis of the encryption function shows that it can output non-printable characters (confirm this for yourself), therefore all output is encoded using Base64 Encoding using the encode and decode functions. For example, the string test encrypted with the key 0x80 (128 decimal) is: 1 2 print(encode(encrypt(b"test", 0x80))) b'90Xz9A==" We can verify that encrypting 90X29A== with the key 0x80 results is "test": i 2 print(encrypt(decode("90Xz9A=="), 0x80)); b'test' Your spies have also converted this code to a Java class and C code