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"That seems impossible," said Samos.
"It is true," said Bosk. "Further, over sixty percent of the language consists of those five letters plus Ar, Ina, Shu and Homan."
"We could still try all possible combinations," said Samos.
"True," said Bosk, "and, in a short message, which this appears to be, we might produce several intelligible possibilities. Short messages, particularly those which do not reflect statistical letter frequencies, can be extremely difficult to decipher, even when the cipher used is rudimentary."
"Rudimentary?" asked Samos.
"There are many varieties of cipher," said Bosk, "both of the substitution and transposition type. I suspect we have before us, in this necklace, a simple substitution cipher."
"Why?" asked Samos.
"It was interpreted almost instantly by the man called Belisarius," said Bosk. "A more complicated cipher, indexed to key words or key numbers, would presumably have required a wheel or table for its interpretation."
"Can all codes be broken?" asked Samos.
"Do not confuse a code with a cipher," said Bosk. "In a code, a given character, or set of characters, will commonly correlate with a word, as opposed to a letter. Codes require code books. Codes, in effect, ca
"Do you feel the enemy would risk a code book, or code device, on Gor?" asked Samos.
Bosk smiled. "It seems unlikely," he said.
"Are there Unbreakable ciphers?" asked Samos.
"Yes," said Bosk, "both from a practical and theoretical point of view. From the practical point of view, if a cipher is used briefly and for a given short message, it may be impossible to break. There is just not enough material to work with. From the theoretical point of view, the unique-sequence cipher ca
Both sender and receiver know, for example, that message six will be randomized in ma
"This is complex," said Samos.
"It requires that both sender and receiver have the deciphering tables at hand," said Bosk. "Thus, although it is more convenient than a code book, it shares some of the vulnerability of the code book."
Samos looked down at the necklace on the table before him. "Why should this be a simple substitution cipher?" he asked.
"I think that it is," said Bosk. "from the ease with which Belisarius read the message. I find it not implausible that it should be a simple substitution cipher because of the simplicity and convenience of such a cipher."
"Is it as secure?" asked Samos.
"The security of this cipher," smiled Bosk, "lies not in itself, as a cipher, but rather, as is common, that it is not understood as a cipher. It is not, for example, a strange message written upon a scrap of paper, calling attention to itself as a secret communication, challenging the curious to its unraveling, but apparently only an i
Samos lifted the necklace. I did not know what secret it contained.
"Further," said he who was called Bosk of Port Kar, "the slave herself did not understand the nature of her role in these matters. She did not, for a long time, even understand that she bore the message. Great security was achieved, too, in the ma
"Worthy of the enemy," said Samos.
"I think so," said Bosk.
"Could we not seize this Belisarius?" asked Samos.
"We do not know where he is," said Bosk. He looked at Iskander, of the Physicians. "If we should be able to seize him who is spoken of as Belisarius, do you think we could derive the cipher key from him?"
"Perhaps," said Iskander, "but I suspect that a spoken word, uttered by Belisarius himself, would, by suggestion, remove the cipher key from his mind."
"Could the enemy be so subtle?" asked Samos.
Iskander, of the Physicians, pointed to me. "I think so," said he. "You see what their power is in such matters."
I looked down.
"Could we, by the use of drugs, obtain it?" asked Samos.
"Perhaps," said Iskander, "but presumably we would encounter numerous keys. Who knows?"
Samos looked at Bosk. "Can you read the cipher?" he asked.
"I do not know," said Bosk. "See the repetitions of the beads. There are several repetitions, to compose the entire necklace. The message itself is thus short."
"It may be impossible to rend?" asked Samos.
"Yes," said Bosk.
Samos looked at me. "I wonder," said he, "why, when finished with this wench, they did not cut her throat?"
I shuddered.
"They apparently feared little," said Bosk. "Their security, they deemed, was impregnable."
"May I speak, Masters?" I asked.
"Yes," said Samos.
"Belisarius," said I, "said that others would not understand the message, even if they might read it, that it would be meaningless to them."
Samos looked to Bosk. "Captain," said he, "begin work."
"I shall, Captain," smiled Bosk. He turned to the slave girl, Luma. "Copy down," said he, "on your paper the order of the beads, in widely spaced rows. Give me then your marking stick and your paper."
"Yes, Master," she said.
In moments her quick hands had accomplished this business and she surrendered to Bosk of Port Kar both the paper and the marking stick.
"We shall begin," said Bosk, "by supposing that the sequence of blue and red corresponds to Eta. The next most common sequence is orange and red. We shall, tentatively, suppose that corresponds to Tau."
I leaned back on my heels, and watched. No one spoke. Samos and Clitus Vitellius were intent. Bosk worked swiftly, but, upon occasion, he seemed angry. More than once, for certain letters, he altered his initial hypothesis of correspondence, substituting another, and sometimes yet another and another.
At last he laid down the marking stick, and, ruefully, viewed the paper before him.
"I have the message," he said, soberly.
Samos turned to the two slave girls who knelt to one side. "Begone, Slaves," he said. Swiftly, in their silk, they fled from the room, commanded by a man.
Bosk looked to Luma. "Yes, Master," she whispered. She, too, rose to her feet and, in her brief, blue tunic, hurried from the room. Under the command of masters, slave girls do not dally.
"Would you wish me to withdraw?" inquired Clitus Vitellius.
Samos looked at Bosk of Port Kar. Then Samos said, "Remain, if you would, Clitus Vitellius, Captain of Ar."
Clitus Vitellius nodded.
I knelt as before, a naked, captive slave.
Bosk looked angrily at the words on the paper before him. "It makes no sense," said he.
"What is the message?" asked Samos.
He called Bosk of Port Kar read from the paper before him: "Half-Ear Arrives," he said. Then he added, "It is meaningless."
"No," whispered Samos, his face white. "It is not meaningless."
"What is the meaning?" asked Bosk of Port Kar.
"When did you give this message, Slave Girl?" demanded Samos of me.
"In the last passage hand, Master," I said.