Cryptosystems

One or more cryptographic primitives are often used to develop a more complex algorithm, called a cryptographic system, or cryptosystem. Cryptosystems (e.g. El-Gamal encryption) are designed to provide particular functionality (e.g. public key encryption) while guaranteeing certain security properties (e.g. CPA security in the random oracle model). Cryptosystems use the properties of the underlying cryptographic primitives to support the system's security properties. Of course, as the distinction between primitives and cryptosystems is somewhat arbitrary, a sophisticated cryptosystem can be derived from a combination of several more primitive cryptosystems. In many cases, the cryptosystem's structure involves back and forth communication among two or more parties in space (e.g., between the sender of a secure message and its receiver) or across time (e.g., cryptographically protected backup data). Such cryptosystems are sometimes called cryptographic protocols.

Some widely known cryptosystems include RSA encryption, Schnorr signature, El-Gamal encryption, PGP, etc. More complex cryptosystems include electronic cash^[25] systems, signcryption systems, etc. Some more 'theoretical' cryptosystems include interactive proof systems,^[26] (like zero-knowledge proofs,^[27]), systems for secret sharing, etc.

Until recently, most security properties of most cryptosystems were demonstrated using empirical techniques, or using ad hoc reasoning. Recently, there has been considerable effort to develop formal techniques for establishing the security of cryptosystems; this has been generally called provable security. The general idea of provable security is to give arguments about the computational difficulty needed to compromise some security aspect of the cryptosystem (ie, to any adversary).

The study of how best to implement and integrate cryptography in software applications is itself a distinct field, see: cryptographic engineering and security engineering.  Louis J. Sheehan, Esquire

Victim Gary Hinman

The LAPD was approached shortly after the Tate-LaBianca murders by two LA Sheriff's Office detectives who told them of the July 31 murder of music teacher Gary Hinman. On the wall of the dead man's living room was written in his own blood "POLITICAL PIGGY," which seemed very similar to the words written at both the Tate and the LaBianca crimes scenes. Also, Hinman had been stabbed to death as had victims at the Tate and LaBianca homes.

Amazingly enough, the LAPD detectives refused to examine any connection between the deaths of Hinman and the people at the Tate house. Furthermore, the LaBianca murders were squarely in the territory of the LA Sheriff's Office and the LAPD had no interest.

Bobby Beausoleil

Had the LAPD detectives bothered to listen to the LA Sheriff's Office detectives, they would have heard that the Sheriff's Office had arrested a Bobby Beausoleil for the Hinman murder. A Beausoleil who had been living with a bunch of hippies led by Charles Manson. But, the LAPD had already decided that the Tate murders were a result of a drug deal gone bad and didn't want to hear about any hippies.

On the other hand, the LAPD had in custody one William Garretson, the caretaker on the Tate estate who claimed that he slept through the entire bloody ordeal. The case against the frightened young man never materialized after he passed a polygraph test.

Officials essentially discounted robbery as a motive for the crimes, even though Rosemary LaBianca's wallet and wristwatch were missing.  In the two homes of these affluent victims there were many items of value, which had not been touched by the killers. Small amounts of cash lying around the Tate home were still in evidence and the purses and wallets of the Tate victims were intact.

The LAPD did investigate three alleged dope dealers that had once crashed a party at the Polanski's, but one by one the men were cleared of any involvement.

Likewise, Roman Polanski was interviewed for hours by the police and agreed to a polygraph examination. On August 15, he returned for the first time since the murders to the house on Cielo Drive, accompanied by psychic Peter Hurkos.

Polanski had been devastated by the loss of his wife and son and was enraged at the media circus that he walked into when he got back to the States. He lashed out at the newspapers for suggesting that he and his wife were Satanists, indulging in sex and drug orgies. "Sharon," he said, "was so sweet and so lovely that I didn't believe that people like that existed...She was beautiful without phoniness. She was fantastic. She loved me and the last few years I Louis J. Sheehan, Esquire spent with her were the only time of true happiness in my life..."

He worried to the police that perhaps he was the target not Sharon. "It could be some kind of jealousy or plot or something. It couldn't be Sharon directly." Polanski did not believe that drugs were a motive for the crimes. His wife, although she had experimented with LSD before they met, was not a big drug user. "I can tell you without question," he told the police. "She took no drugs at all, except for pot, and not too much of that. And during her pregnancy there was no question, she was so in love with her pregnancy she would do nothing. I'd pour a glass of wine and she wouldn't touch it."