IGCSE Computer Science Paper 1 Crossword: 2.3 Encryption and 3.1 Computer Architecture (Modules 204–217)
Name:
Date:
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Crossword
Read each clue and write the matching term in the grid. Numbers in brackets show the letters in each word.
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Across
- 3. The receiver shares their public key, the sender encrypts with it, and only the receiver's private key can ______ it. No secret key is shared, so an interceptor sees only ciphertext. Word 5 of: _______ ____ public ___, _______ ____ private ___ (7)
- 5. Word 3 of the term in 2 Down: _________ vs __________ (10)
- 6. Word 1 of the term in 4 Down: _______ ____ _________'s public ___ (7)
- 9. Word 3 of the term in 7 Down: Von _______ ____________ (12)
- 10. Word 2 of the term in 4 Down: _______ ____ _________'s public ___ (4)
Down
- 1. A full-mark answer uses the key terms correctly and gives the steps in order: ______ is encrypted with a key into ciphertext. Encryption does not stop interception. Word 1 of: _________, ___, ciphertext (9)
- 2. Use ______ if both sides can already share a key safely; use ______ for strangers, such as a customer and a website. Justify the choice with 'because'. Word 1 of: _________ vs __________ (9)
- 4. To send a secure message, the sender encrypts the plaintext using the receiver's public key, not their own. Only the receiver's private key can decrypt the ciphertext. Word 3 of: _______ ____ _________'s public ___ (9)
- 7. A computer design where instructions and data share the same main memory (RAM) and the CPU fetches them one at a time. This is the stored program concept, named after John von ______. Word 2 of: Von _______ ____________ (7)
- 8. The secret half of a ______ pair. Only the owner keeps it, never sends it, and uses it to decrypt data that was encrypted with their public ______. Word 2 of: private ___ (3)
Answer Key
IGCSE Computer Science Paper 1 · Modules 204–217
1P
2S
3D
E
C
4R
Y
P
T
L
Y
E
5A
S
Y
M
M
E
T
R
I
C
I
M
I
N
6E
N
C
R
Y
P
T
7N
T
T
I
E
8K
E
9A
R
C
H
I
T
E
C
T
U
R
E
X
I
N
M
Y
T
C
10W
I
T
H
A
N
N
Across
3DECRYPT — The receiver shares their public key, the sender encrypts with it, and only the receiver's private key can ______ it. No secret key is shared, so an interceptor sees only ciphertext. Word 5 of: _______ ____ public ___, _______ ____ private ___
5ASYMMETRIC — Word 3 of the term in 2 Down: _________ vs __________
6ENCRYPT — Word 1 of the term in 4 Down: _______ ____ _________'s public ___
9ARCHITECTURE — Word 3 of the term in 7 Down: Von _______ ____________
10WITH — Word 2 of the term in 4 Down: _______ ____ _________'s public ___
Down
1PLAINTEXT — A full-mark answer uses the key terms correctly and gives the steps in order: ______ is encrypted with a key into ciphertext. Encryption does not stop interception. Word 1 of: _________, ___, ciphertext
2SYMMETRIC — Use ______ if both sides can already share a key safely; use ______ for strangers, such as a customer and a website. Justify the choice with 'because'. Word 1 of: _________ vs __________
4RECIPIENT — To send a secure message, the sender encrypts the plaintext using the receiver's public key, not their own. Only the receiver's private key can decrypt the ciphertext. Word 3 of: _______ ____ _________'s public ___
7NEUMANN — A computer design where instructions and data share the same main memory (RAM) and the CPU fetches them one at a time. This is the stored program concept, named after John von ______. Word 2 of: Von _______ ____________
8KEY — The secret half of a ______ pair. Only the owner keeps it, never sends it, and uses it to decrypt data that was encrypted with their public ______. Word 2 of: private ___