<< < 1 2 3   Sort: Rank

What Is PKCS5Padding?
This section describes what is PKCS5Padding - a schema to pad cleartext to be multiples of 8-byte blocks.
2016-06-16, 15993👍, 8💬

💬 2016-06-16 yo: hola pescado

💬 2016-04-04 ankit: this is me.

💬 2016-01-28 John: Herong, thanks a lot.

💬 2016-01-27 Herong: John, the schema of PKCS7Padding can be described as below: Pad the input at the trailing end with k−(l mod k) octets with the s...

💬 2016-01-24 John: For PKCS7Padding, what is the schema? I'm interested to what is after 0x0909090909090909099

(More comments ...)

What Is a Digital Signature?
This section describes what is a digital signature and what is the process of generating and verifying digital signature from a message.
2016-04-26, 2463👍, 1💬

💬 2016-04-26 santosh patil: Its easy to understand

"openssl pkcs8" Converting Keys to PKCS#8 Format
This section provides a tutorial example on how to convert a private key file from the traditional format into PKCS#8 format using the 'openssl pkcs8' command. Keys can still be encoded with DER or PEM with or without DES encryption in PKCS#8 format.
2016-04-12, 4958👍, 1💬

💬 2016-04-12 Nishant Desai: Does anyone knows any library by which i can execute openssl pkcs8 -topk8 -in openssl_key.pem -inform pem -out openssl_key_pk8_e...

Certificate X.509 Standard and DER/PEM Formats
This chapter provides tutorial notes and example codes on certificate content standard and file formats. Topics include X.509 standard for certificate content; DER encoding for certificate binary file format; PEM encoding for certificate text file format; exchanging certificates in DER and PEM forma...
2016-04-10, 130👍, 1💬

Summary - Migrating "keystore" Keys to "OpenSSL"
This section describes high level steps on how to migrate a private key generated in a JKS (Java KeyStore) file to an 'OpenSSL' key file. The key step is to convert a JKS file into a PKCS#12 file with 'keytool'.
2016-04-09, 102👍, 1💬

Cryptography Basic Concepts
This chapter describes some basic concepts of cryptography: what is cryptography, what is function and what is encryption.
2016-04-07, 2032👍, 4💬

💬 2016-02-03 dinesh: thanks

💬 2015-12-28 Herong: Malini, RSA is good example of cryptosystem. Read Introduction of RSA Algorithm for more information.

💬 2015-12-28 malini: need cryptosystem

Certificate in PEM Format
This section describes what is certificate PEM (Privacy Enhanced Mail) format - A format uses PEM idea to convert a certificate in DER format to a message of printable characters. The conversion uses the Base64 encoding.
2016-03-30, 3071👍, 2💬

💬 2016-03-30 Herong: Bcbin, why don't you post your question here? Maybe others can help you too. Or send me an email directly.

💬 2016-03-27 bcbin: my name is bcbin, my email is bcbin@yahoo.com. please connecting me. i need you help ):

Key Schedule (Sub-Keys Generation) Algorithm
This section describes the Blowfish Key Schedule (Sub-Keys Generation) algorithm. It uses the binary representation of the fractional portion of constant Pi - 3.1415927... as initial values.
2016-03-17, 1054👍, 2💬

💬 2016-03-17 Herong: Hi Yogita, Blowfish(T) function refers the Blowfish algorithm described in the previous tutorial: Blowfish Cipher Algorithm.

💬 2016-03-16 YOGITA: what is the function blowfish(T) here? Send the pseudo code

Viewing Components of RSA Keys
This section provides a tutorial example on how to view different components of a pair of RSA private key and public key using the OpenSSL command line tool.
2016-03-14, 1508👍, 2💬

💬 2015-10-02 Herong: Looks like someone is testing Base64 encoding here :-)

💬 2015-10-01 1: CSENry/M1h2AhxGSxQluy4b1ynzBGWeO320C AwEAAQJAbQQn... IQCoo0AdFXm789FfHuB+mVIKNtBLTAQNaMuX z6lXl7Ib7Q==

Viewing Components of Certificate Signing Request
This section provides a tutorial example on how to view different components of a CSR (Certificate Signing Request) for your public key with OpenSSL.
2016-03-14, 555👍, 3💬

💬 2014-03-29 Herong: Hi Mike, Sorry for the inconvenience. HTML tags are supported, but they are limited to admin users only to reduce spamming and h...

💬 2014-03-23 Mike: Wow. What a waste of time trying to make a legible comment post. No instructions on how to get a paragraph break, include a angl...

💬 2014-03-23 Mike: You made a note in "Viewing Components of Certificate Signing Request" where you said, "The request is signed with my private ke...

Key Pair Sample Program - JcaKeyPair.java
This section provides a tutorial example on how to write simple program to generate a pair of private key and public key for the RSA or DSA algorithm.
2016-03-01, 775👍, 1💬

💬 2016-03-01 Shruti: thanks

Illustration of RSA Algorithm: p,q=7,19
This section provides a tutorial example to illustrate how RSA public key encryption algorithm works with 2 small prime numbers 7 and 19.
2016-02-29, 1060👍, 3💬

💬 2015-11-01 Herong: Jun, AES algorithm is added now, see Introduction to AES (Advanced Encryption Standard).

💬 2015-10-17 Herong: Jun, thank you for pointing out the mistake. I will correct it in the next version. AES will also be included.

💬 2015-10-16 jun: thanks a lot. your book makes everything clear for me except that I have not found a char for AES. By the way, I think "Generati...

RSA Implementation using java.math.BigInteger Class
This chapter provides tutorial notes and example codes on RSA implementation using Java BigInteger class. Topics include introduction of the java.math.BigInteger class; generating large probable prime numbers; generating RSA public key and private key; validating RSA keys; determining cleartext and ...
2016-02-29, 2517👍, 3💬

💬 2016-02-29 Herong: sah, is that an encoded comment?

💬 2016-02-28 sah: 7C4A8D09CA3762AF61E59520943DC26494F8 941B

💬 2014-02-06 Chinmayee: Searching for a book on RSAKey generation and got your link. Have not gone through the pdf yet. If find it good, will go for the...

DESCipherTest.java - DES Cipher Algorithm Illustration
This section provides a tutorial Java program, DESCipherTest.java, to illustrate how DES cipher algorithm works.
2016-01-24, 887👍, 1💬

💬 2016-01-24 Joe: Output

Steps of Using DES Algorithm in JDK JCE
This section describes how to use DES algorithm provided in the JDK JCE package. Steps include building a secret key object from key material; creating and initializing a cipher object.
2016-01-24, 702👍, 1💬

💬 2016-01-24 Joe: Very nice

What is ECB (Electronic CodeBook) Operation Mode?
This section describes what is ECB (Electronic CodeBook) Operation Mode - each plaintext block is encrypted independently without any input from other blocks.
2016-01-10, 2380👍, 2💬

💬 2016-01-10 Todd: Thanks!

Introduction to AES (Advanced Encryption Standard)
Tutorial notes and example codes on AES algorithms. Topics include introduction of AES (Advanced Encryption Standard); AES encryption algorithm; AES key schedule (round keys) algorithm and illustration example; MixColumns procedure algorithm; AES decryption algorithms.
2015-11-27, 251👍, 1💬

What is OFB (Output FeedBack) Operation Mode?
This section describes what is OFB (Output FeedBack) Operation Mode - each plaintext block is XORed with the current output block to be the ciphertext block. The current output block is the encrypted version of the previous output block.
2015-11-13, 1364👍, 2💬

💬 2015-11-13 Ashish: Hello world!

Generating New RSA Key Pairs
This section provides a tutorial example on how to generate a new pair of RSA priviate key and public key using the OpenSSL command line tool.
2015-11-03, 857👍, 1💬

💬 2015-11-03 Juli: Thanks

Cryptography Terminology
This section provides descriptions on some commonly used cryptography terminologies
2015-10-24, 2179👍, 1💬

💬 2015-10-24 dexter aparicio: this site is my favorite reference on cryptography topics

Validating a Certificate Path with OpenSSL
This section provides a tutorial example on how to perform validation of a certificate path with the 'openssl verify' command.
2015-10-14, 16779👍, 5💬

💬 2015-10-14 Herong: Karnan, if the issuer is a root CA, issuer certificate should be in your trusted certificate store. If the issuer is an intermed...

💬 2015-10-13 karnan: how to get issuer certificate

💬 2015-09-02 Liang: Thanks, Yang, This is a very helpful for understanding the basic concept of Crypto/SSL.

💬 2015-08-14 Chris: If you have to specify an intermediate as trusted, that means the intermediate is not qualified to be a signer.

💬 2015-08-12 Aleksandar Kostadinov: I see a strange thing: openssl verify -CApath . &lt;(cd /tmp ; cat server.pem intermediate.pem) That does not work if interm...

DES Key Schedule Algorithm Illustration Program Output
This section provides the execution output of the tutorial Java program, DESSubkeysTest.java, to illustrate how DES key schedule algorithm works.
2015-08-09, 1747👍, 1💬

💬 2015-08-08 nishant nath: I loved it

Subkeys of 3DES Encryption
Hi Doc, I have subkeys recovered through DPA. Can 3DES.c be modified to accept these subkeys as inputs for a cryptographic operation? Alternatively, can the main 3DES key be reverse generated from the subkeys? Thanks. jeffrey****alis@gmail.com
2015-07-23, 2311👍, 1💬

💬 2015-07-22 Herong: Hi Jeffrey, Which 3DES.c are you referring to? Can you tell me where I can see the code?

<< < 1 2 3   Sort: Rank