Public key cryptography is 30 years old
On the occasion of the 30th anniversary of “civilian cryptography” in America, a solemn event was organized, where the founders of modern cryptographic science, including Whitfield Diffie and Martin Hellman, were invited.
As the participants noted, the thirty-year history of public cryptography was accompanied by pressure on civilian cryptographers from government agencies. But the biggest problem for cryptography today is not pressure from the security services at all, but lack of usability. Due to the lack of convenient software products, even the most advanced geeks still send their emails via the Internet in plain text format.
In June 1976, the fundamental work of Whitfield Diffie and Martin Hellman (Martin Hellman) by American cryptographers “Multi-user cryptographic techniques” was published. In this paper, the principles of asymmetric cryptography were first described, as well as an algorithm, which was called the Diffie-Hellman algorithm. Ralph Merkle is not mentioned among the authors, although he also worked on this topic. He, too, can rightfully be considered the co-author of this, without exaggeration, a great invention.
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Asymmetric cryptography algorithms use two keys: one for encrypting a message, and the second for decrypting it. The keys are so mathematically related that the data encrypted with one key can only be decrypted by the other (it is paired). Each user has two keys: the public key and the secret key, and the public key can be put on public display (put in the public directory). Thus, knowing the user's public key, you can compose a message that only the owner of the pair secret key can read, and no one else. The most important thing is that in this case the message itself can be transmitted via open communication channels without fear of interception.
The invention of public-key cryptography has become a breakthrough in this science. In our time, the most famous system with public keys is, perhaps, the RSA system. The RSA cryptosystem is a block cipher in which the plaintext and ciphertext are integers from 0 to N -1 with some N. The RSA system is based on the exponentiation function in modular arithmetic, with arithmetic being performed on composite numbers.
Knowing the plaintext M , the module N and the exponent e , we can calculate M ^ e mod N. The exponentiation function is a one-way function in terms of extracting both roots and logarithms. For some values of M , N, and e, it becomes very difficult to reverse this function — it requires huge computational resources and time.
Nowadays, not every user understands the basics of cryptography. It is this fact, and not the pressure from the state special services, that is the main obstacle on the path to the universal introduction of reliable crypto-cipher.
As the participants noted, the thirty-year history of public cryptography was accompanied by pressure on civilian cryptographers from government agencies. But the biggest problem for cryptography today is not pressure from the security services at all, but lack of usability. Due to the lack of convenient software products, even the most advanced geeks still send their emails via the Internet in plain text format.
In June 1976, the fundamental work of Whitfield Diffie and Martin Hellman (Martin Hellman) by American cryptographers “Multi-user cryptographic techniques” was published. In this paper, the principles of asymmetric cryptography were first described, as well as an algorithm, which was called the Diffie-Hellman algorithm. Ralph Merkle is not mentioned among the authors, although he also worked on this topic. He, too, can rightfully be considered the co-author of this, without exaggeration, a great invention.
')
Asymmetric cryptography algorithms use two keys: one for encrypting a message, and the second for decrypting it. The keys are so mathematically related that the data encrypted with one key can only be decrypted by the other (it is paired). Each user has two keys: the public key and the secret key, and the public key can be put on public display (put in the public directory). Thus, knowing the user's public key, you can compose a message that only the owner of the pair secret key can read, and no one else. The most important thing is that in this case the message itself can be transmitted via open communication channels without fear of interception.
The invention of public-key cryptography has become a breakthrough in this science. In our time, the most famous system with public keys is, perhaps, the RSA system. The RSA cryptosystem is a block cipher in which the plaintext and ciphertext are integers from 0 to N -1 with some N. The RSA system is based on the exponentiation function in modular arithmetic, with arithmetic being performed on composite numbers.
Knowing the plaintext M , the module N and the exponent e , we can calculate M ^ e mod N. The exponentiation function is a one-way function in terms of extracting both roots and logarithms. For some values of M , N, and e, it becomes very difficult to reverse this function — it requires huge computational resources and time.
Nowadays, not every user understands the basics of cryptography. It is this fact, and not the pressure from the state special services, that is the main obstacle on the path to the universal introduction of reliable crypto-cipher.
Source: https://habr.com/ru/post/4619/
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