Tag: #cryptography

An encrypted diary using OpenSSL

Generate a master keypair. Encrypting each diary entry with a one-time shared secret. Encrypt the shared secret with the public key. Decrypt entries using the private key and the shared secret. 2017-12-03

How do I create a message digest using openssl?

Create message digests using the openssl dgst command, specifying the hash algorithm (e.g. -sha512) and optionally signing with a shared password using -hmac. 2017-03-13

How do I hash a password with openssl?

The openssl passwd command hashes passwords using the outdated crypt algorithm, with truncation to 8 characters - a poor choice for secure password hashing. 2017-03-12

How do I generate random bytes with openssl?

Generate random bytes with openssl rand, which uses a PRNG seeded with entropy from ~/.rnd. 2017-03-10

How do I encrypt text with openssl?

Encrypt and decrypt text using the openssl enc command with a password and AES-256 cipher. The encrypted text is base64-encoded. 2017-03-09

How does a stream cipher work?

A stream cipher works like a one-time pad, but uses a pseudorandom “keystream” from a PRNG seeded by a secret key and nonce, preventing attacks based on pad disclosure or reuse. 2016-11-21

What is symmetric cryptography?

Symmetric cryptography uses a shared secret key for both encryption and authentication, providing confidentiality and integrity. We look at the API, HMAC, and Authenticated Encryption. 2016-11-19

All content copyright James Fisher.